First of all, hello and welcome Slyfox! I have been playing quite a bit of Renown myself through the grinding process so I found your post interesting and I noticed a lot of similarity in our impressions.
The archetype is obviously pretty aggressive, curve is a big deal, most builds should be playing a few 1-drops and a few more 2-drops.
On that note, Anointer of Champions should probably see play. It's good for making combat with your renown creatures particularly difficult. It shouldn't necessarily be a full three-of, but some copies should almost always make the cut. I toyed with Elite Vanguard, but I don't really think it's good enough. It just gets outclassed far too easily. Kytheon is also obviously great, so that's something that you should always play. Finally, there's Sunblade Elf, which is just an excellent card, and might just be the best reason to be playing this archetype. The Elf should be a three-of in every list.
As for the 2-drops, Undercity Troll is awesome. Every version of this archetype should absolutely play all three. Same with Consul's Lieutenant. Depending on how aggressive you want to be, it can even be correct to play some number of Topan Freeblades, especially since 2-drop renown creatures are very good with Valeron Wardens.
I agree that this archtype wants to be aggressive. You always want to be swinging in and pressuring your opponent.
Anointer of Champions plays better than it looks on the surface. It can help make math tricky for your opponent and it helps push through blockers in a pinch. I think it should be a 1 or 2 of depending on how many other 1-drops you have slotted in.
Elite Vanguard is fine but it often becomes irrelevant (especially online against
Perilous Myr) and can set you up for a nasty two-for-one with
Twin Bolt seeing a lot of play in thopter lists.
Kytheon, Hero of Akros I haven't unlocked this card yet. I imagine it's incredibly strong as an early-drop and easy to flip when the majority of your deck is creature-based. His planeswalker side adds a lot to the strategy by forcing your opponent to attack, adding to the board, or simply making your guy indestructible when you swing in. Overall, he looks really good in this type of strategy. I think you overvaluing
Sunblade Elf. I really like this card because it gives you another -good- 1-drop and it let's you use your mana late game but I certainly don't think he is an auto-inclusion simply because he is a 2/2 at best and I never wanted to swing in with him before turn 5 when I can pump him. Overall, he's decently a good card but he is not great off curve and it can be hard to balance the manabase to support him effectively (more on that later).
Undercity Troll is great also. He's flexible and easy to cast. You can turn him sideways on the next turn (assuming you leave up regeneration) with no real setback. The problem is that I don't feel like he fits into the swarm strategy. He's more of a single threat that I always leave obligated to protect. At best he is a 3/3 (which is relevant) but it's not the strongest two-drop in my opinion. One concern I have overall is your idea regarding the mana. You say to include all of the Elves and the Troll...and
Consul's Lieutenant? I don't see how you can manage turn 1 untapped Forst into double WW for Consul's Lieutenant. As you said, you really want to be on curve so you kind of have to decide how much green you really want in the renown deck and Consul's Lieutenant requires a lot of white to fix in on curve. Finally, you might think I'm crazy, but
Topan Freeblade is probably the best two-drop in my opinion. Even better than Undercity Troll and Consul's Liutenant. Topan Freeblades become a 3/3 (like Undercity Troll) but they can attack AND block. Consul's Lieutenant is great but it kind of overlaps with Sunblade Elf and I don't think you need that many pump effects. I would side with one or the other. Also the 2 toughness (max) on Consul's Lieutenant makes it vulnerable to Twin Bolt and
Fiery Impulse.
As for some of the other creatures:
I tried Nissa, and I actually don't really think that she's good enough. She is a form of reach, but I find Rogue's Passage to do the job much better. Stalwart Aven is interesting, and I could definitely see playing a copy or two as a low opportunity cost evasive creature with good stats, but it's nothing exciting, and it's unlikely that four copies is the right number. Vryn Wingmare is another interesting choice. The deck is very creature-dense and making all of your opponent's removal less efficient is a great way to win games against more controlling decks, plus the body is a very decent way to put evasive pressure on your opponent. I find it likely that it is correct to play both copies. Valeron Wardens is quite good. When you play a large number of 2-drop renown creatures, it will cantrip fairly easily, and with combat tricks or even just against slower starts, it can renown itself and give you a big 3/5 as well as draw you a card. This is something I think should be played as a two or three-of in most of these decks. Citadel Castellan is just great, so three copies there. The deck is aggressive, so the top end should be sparse, but there are definitely some great options. Kytheon's Irregulars is amazing, so the two copies of that should go right in. Patron of the Valiant and Outland Colossus are massive finishers in this deck, and I think I could settle on playing two of each. The Patron's counter ability is extremely relevant in this deck and it's well-statted, and the Colossus is just a big deal. I've even been trying Juggernaut, as it's great with tricks and Rogue's Passage and just generally is a big threat.
Nissa, Vastwood Seer is another card I do not own. However, I agree that it seems underwhelming. You don't want to be playing a 2/2 on Turn 3. You'd rather swing in and use
Wild Size or add more to the board through the 3/2 Renown Knight or the 1/3 Flyer. The 1/3 Flyer isn't very good in my opinion. This card seems much more defensive than offensive and the 2 damage (after renown) has rarely matter in every game I played him in. I think he's fine but definitely less appealing than the 3/2 Knight.
Vryn Wingmare is also a very underwhelming card. At best it let's you prolong a Languish but the 2/1 body doesn't match up well against any other flier in the format (trading with thopter tokens and the 1/1 faerie). It also prevents you from playing your Wild Size on curve which, in my opinion, is the ideal play turn 3. I usually pass on this card.
Valeron Wardens is the next best thing you can do on turn 3 (again, in my opinion) and it gets even better if you're on the play and your opponent didn't add to the board on turn 2. It usually nets me 2-3 cards a game or just dies to removal (which saves a better creature anyway). This card is great.
Citadel Castellan is really strong but probably the least best thing to do on turn 3 because you're only adding an additional body to the board and it's not being as proactive as the other choices. Still, it's solid, and I wish I had 3 copies to test this further. So far, it's just an overall good way to round out the 3-slot.
Kytheon's Irregulars is a reason to stay heavy white. Being able to activate this twice is completely game changing. He doesn't tap so you can even use this the same turn you play him with enough mana. This card is seriously insane whenever he sticks for more than a turn. I've won a lot of games off the back of this card.
Patron of the Valiant is a 4/4 flier at worst which isn't a bad deal. The counters are usually 'win-more' for me though because if I have renown creatures in play when I cast this on turn 5 I'm usually already doing really well.
Outland Colossus is the reason to add more green sources. The unique ability to only be blocked by one creature makes him an 'abyss' for your opponent every turn. They have to answer him or they just lose. This guy is the perfect thing to top the curve. I haven't tested Juggernaut but I recommend looking at the 2/2 elf guy with Scry2 because he usually is just draw a card and/or hide excess lands.
As for everything else:
Wildsize is excellent in this deck. It's almost always a two for one, and it even gives trample so that your renown creatures still trigger. Definitely the combat trick of choice. I've tried a couple of removal spells in this deck. The one I settled on is Suppression Bonds, as it gets rid of a blocker no questions asked. I also tried Celestial Flare, but it was a little too hard to land reliably and just didn't pay off well. Wild Instincts does a similar job to Suppression Bonds, but just does it a little worse. There are even matchups where the Instincts would be better for its ability to add 2 damage to your subsequent attack, but I am certain that the Bonds is a better choice. Finally, Rogue's Passage has turned out to be great in this deck. It is a very easy way to get reach and can present a very quick, hard to interact with clock with any of the larger ground creatures in the deck. This is a clear three-of for me after playing with it a bit. I could also see Grasp of the Hieromancer being a beating in this deck, but I haven't tested it so I can't speak to it. I also tried Hixus, and I think that he's a trap card. When you just want to be attacking with everything every turn, he's little more than a 4/4 for 5, but I suspect that people will try to play him anyway because he is objectively powerful.
This is a classic creature beatdown deck, and I've been doing most of my grinding with it. It seems strong enough and surprisingly synergistic.
This response is getting quite long so I'll just get to the main points here. Wildsize is the best card in the 3-slot. Suppression bond is the best removal because it can be used to answer just about anything outside of like thopter spy network. Celestial Flare is good but only if you are heavy white (20 + white sources). Wild Instincts is fine but I agree that Suppression Bonds is usually better unless you are all out aggro and killing your opponent on that turn or the next. Rogue's Passage is hard to test because of all the WW and GG in most of my lists. I imagine it's good but I wouldn't run multiple copies; one seems like enough to me. Grasp of the Hieromancer and Nimbus Wings are both excellent auras that can be a viable conclusion. Just depends on how many 2-slots are open. I would lean towards Nimbus Wings because I like Topan Freeblade. Hixus, Prison Warden isn't good. He's a 4/4 for 5 as you said and, at least for me, he is very inconsistent even if you manage to blow out your opponent if you don't time it right (like me, I'm an idiot), he does nothing. You want to pay very close to attention because the timer is so quick. I don't think he's very good...
I also just realized that I forgot to mention Archangel of Tithes, which is just insane, so yeah, one copy in any build of this deck, especially since the deck tends to be a bit more white-heavy.
This is why I kept bringing up heavy-white lists. Archangel of Tithes hinders your opponent's mana so much and it's easy to take over the game after it sticks. The biggest problem I have with this card is that it dies to Reave Soul and that's fairly common with all of the U/B control decks running around on Steam. Overall, great card, but it requires a big commitment and can not give you the pay off if it's a bad matchup...
To wrap things up, I think you have a lot of valid points and I agree with the majority of them. You clearly have a lot of experience with the deck already. Thank you for sharing your experiences with those who are interested in the archetype. I hope I can some additional value to your post by sharing my own experiences.
edit: Although I don't have all of the cards for an optimal G/W deck I don't think it's positioned well for multiplayer. At least in my experience. I have lost to a lot of U/B and G/B midrange/control decks over the past week and G/W just doesn't have the card advantage to keep up. They usually have a lot more answers than you have threats and eventually you just fall behind too far. I think that's mainly because you want to be an aggro deck but there is a lot of cards that slow you down and make you more mid-rangey in Renown. I think a mono-W deck may be better than G/W for multiplayer but again this is just my based on my experiences so feel free to test in your meta and come to your own conclusions.