I do feel cutting a Station and 1-2 Bombers would be wise. You could then either put in more sac outlets, or splash another colour.
Thorn-Thrash Viashino isn't a bad card here. It's a sac outlet and you can still get value from it even if you don't draw any Green mana (or just use Shardlands as a source) but if you do, Trample is
very hard to deal with, and as it will always enter as a big card, it does limit what can remove it. If they can't (topdecking for example) it could easily kill the next turn.
Mycoloth is obviously absurdly good, and one of the best cards in the game. It's also nuts with Warstorm. Kresh is great too, but has the same drawbacks as Rockslides, so if you aren't sold on them, you won't be on him.
Otherwise Chasm Skulkers are very, very, very good with Blasting Station as if you change the settings and turn auto resolution off, you can sac every Squid the turn they enter.
My advice would be to cut some of the fat and return to Jund!
-2 Bombers
-1 Blasting Station
-1 Quest for the Gravelord (or other card)
+2 Mycoloth
+2 Thorn-Thrash Viashino
In regards to Rockslides, I agree, they aren't fantastic in sac/steal decks as they can be too slow to grow, but you're in a pure sac deck, where I feel they are exceptional. I run a Blasting Station deck in Izzet colours (using Skulkers, and with Jalira as my alt outlet), and he's an MVP there. I'd strongly urge you to at least give them a try.