Haven’t really played much of Damnation difficulty (5), but have played a good amount of Heresy (4) with my Sharpshooter. Don’t quite remember everyone using the same guns, though I was using that Infantry Lasgun for it and performed pretty well. It has lots of ammo to deal with all the ranged spam and for the most part, you don’t really need armor pen against most specials and non-specials.
That’s somewhat fair, but that’s not exactly an ammo thing, they have a heat system to make up for it, the Peril quelling seems pretty fine to be honest, if you’re BBing (I’ve only really played 1-3 difficulty, not leveled up Psyker fully yet), you only need to not be 100% when starting cast to not pop (and you can ult while blowing up to cancel it). So a tiny vent to 99% and a BB lets you do it fine. With BB you can hit through Bulwark shields and wear down armored enemies pretty easily too, as well as having the benefit of killing retreating enemies (Trappers, Hounds, Bombers) while they’re in cover. Or prep one for them coming around a corner (though that doesn’t feel quite as smooth as it should, clicking too quickly can cancel the charge).
I’m not sure why only the ‘generic’ weapons have multiple versions, but the reasons the others do is variation in how the weapons work and act. Adjusted movesets and statlines. I don’t even really like the Force Sword on the Psyker, I use the Maccabian Saber more.
I won’t defend the store, it’s awful, but I also don’t think the solution is to cap item builds. I do agree with some of the things in this post and what you said in that post is right too. If rerolling does work like that it’d suck. Clearly the game isn’t totally finished, but I don’t think it’s in the worst spot possible. I’ve played like 100 hours already and it’s been pretty fun, I miss leaderboards for joking around with my friends with, but it’s far from being a bad game where you can’t try anything too.