The Tavern

Minotaurs should start with pissed off mutations.

I think you could design an interesting race around having berserkitis, but I wouldn't just tack it on to minotaurs; they're generally recommended to newbies and it's nice to have an easy race for people learning the game.

No, it should be minotaurs, because they have a cultural tradition of being angry. And they are related to bovine. And in depictions of bullfighting, the bull is enraged by the red cloth.

I think it's important to build off of cultural tradition, rather than introducing new species that nobody has ever heard of. For example, I don't know what a palentonga is. I don't know if it's based on some very obscure mythology or they just made it up. I googled it and only came up with dungeon crawl. So, there's absolutely no connection there.

Berserkitis is a very scary mutation.

If you'd like to try out how a species with berserkitis plays, I'd recommend trying a few games with djinn on the bcrawl branch (available on eg underhound.eu:8080).
I haven't been brave enough to try a melee djinn yet. I think the proposed change would make Minotaurs very unpopular.

This view makes complete sense and it would be great theme. I just want to gently warn you that 'theme' tends to come secondary to game play for the developers, so they'll be more concerned with how it affects gameplay. As mentioned, Berserkitis is a very bad mutation to have, and so it would effectively just make playing minotaurs harder. As they get recommended to new players, that's not something that I expect would happen.

There's plenty of other races that can explore temperamental/stubborn/berserker as well as bulls, for example the djinn is a fantasy creature known for being hot headed and deceitful. It isn't a race in the main branch, but you can play them in the fork petercordia mentioned.

Or maybe Trog could suppress beserkitis? After all Then complete newbies could happily continue playing MiBes. (and as a side effect it really impresses the importance of god choice.)
Maybe even link beserkitis to some XP level, so other classes have a decent chance of finding a Trog altar before it kicks in.

That will have the negative side effect, though, of discouraging newbies from trying other deities. Also, it seems pretty consistent that leveling up never makes a character weaker (except for an unlucky Ds roll, but with the reform of Demonic Guardian even that's less of a problem); this would break that.

I don't think "species that can only worship one god" is a good design decision.

Berserkitis is so bad that having it basically means you can't risk melee ever.