Drawing is just part of the game.
I've had my fair share of dealing with people who rare draft and people who try to jam 3-5 color goodstuff decks. If you're at the point of reading signals, your only bet really is to try to read the signals one seat to the right of the person rare drafting. Rare drafting in M15 is really stupid though, bc the set is overall garbage $-wise. Regardless, if this is a personal play group, you can just say you're not going to draft with someone who's rare drafting, and begin a serious discussion about banning them. Rare drafting is a selfish, dick move that defeats the purpose of a playgroup. Picking up an off-color Soul might be a hate draft though, particularly Soul of Theros, which is more or less unbeatable in the format. If this is a store you can complain but there's not a lot that they can do about it, sucks I know.
Usually players on your left drafting goodstuff decks don't affect your draft much because you're only getting one pack from them. If they decide to go into your color pack 2 though it can feel like it's ruining your draft. There isn't much to do about it, because a large number of drafters draft goodstuff decks and move into the color with the most goodstuff cards they have and use that as a method to read signals. There's not a lot you can do about bad drafters.
I feel you though. My last draft was "ruined" when the player to my left was given, explicitly by his friend, all the green cards I was cutting from him pack 1. I went 2-1 for third, losing to the guy who got a pick 6 Cone of Flame
The draft before that I got third again, going 3-1, mostly as a result of the guy on my right opening a blue bomb (my color--he was RW up to that point) pack 2 and deciding to force the color pack 2 and pack 3.
I like your deck overall, but I'm beginning to be less and less impressed with
Siege Wurm. I think I keep trying to jam it as a 4-drop, and then hemorrhaging my life total on the back swing from my opponent. I feel like
Roaring Primadox is where you want to be there. 4-mana 4/4s are good, and you have enough cheap creatures with ETB affects that it could've given you some serious value. A second activation of Totem feels awesome, and a second activation of a wayfinder really fills your yard while ensuring you're hitting your land drops, and zapping your opponent's graveyard while you give yourself some reach with Maggot can be some serious game. That's just my limited Johnny intuition though.
I've come around on Lava Ax too. In previous formats I found it a lackluster 23rd card, but in M15 there is enough cheap evasion at 2, 3, and 4-drops on your curve that a T7 Ax or Stoke the Flames can seal the deal.
Forge Devil also does a lot of work killing pretty much every relevant 2-drop, and
Scrapyard Mongrel can do a lot of work as well. I still don't think it's better than a 20th card, but hey, if Jon Finkel can jam 3 in a deck I should at least reevaluate my conclusion.