^as Rorschach said.
-Kasparov is obvious.
-There are basically 2 “hidden quests” for +1 skill. The other is Act V. Both +1 skill come from ultimate difficulty. I say “hidden” for the act V quest as it is not really hidden but also is not obvious, considering the way it is triggered.
So keep playing through, and you’ll eventually get them through the story.
Purifier is the new and imroved version of the Pyromancer
Crate is not great at class skill or item balance, so this is sadly the case.
However, GD offers lots of options for different playstyles. If you like to zerg everything, look to the top spreadsheet builds. If you feel finesse and learning the individual boss mechanics in more detail is interesting, then Pyro is fine.
Pyro also offers a variety of styles and is really good for learning the game fundamentals. Don’t be hesitant to tweak skills and try various settings. Keep in mind that if self-found, you simply might not find some set pieces or recipes and you will have to improvise.
Further, as you learn the areas, you can juggle resistances as you see fit. They don’t all have to be capped at all locations. That’s a crucible mentality.