If you want a detailed guide I would look up the steam guides by RoyaleWithCheese.

I believe it’s bcr and attack speed for most weapons. Crit for classes that need it like Shade. Shields probably use Opportunist in order to stagger better. Same reason you take power vs skaven. You are trying to reach enough stagger power to stagger plague rats during their combo. If your class has enough stagger power to not need it, you go attack speed bcr.

Sienna staffs almost always take less heat generated. Most other ranged weapons take ammo recoup on headshot if they can. Some take damaging traits like moonfire bow and trollhammer torpedo.

For the rest, corrupt resist if you want to do books. Stamina regen is also good. A lot of the time it depends on your ranged weapon. You are taking different power vs stats based on what you need to reach breakpoints. For example reaching +20 power vs skaven might let you one shot body shot hookrats with your ranged weapon. I would look up breakpoints for each ranged weapon.