1. When I hit a Mob, particularly a boss, with Froststrike, they sometimes resist the Damage partially (mostly 25%, I think). Since this is a severe DPS loss, is there any way to prevent this from happening? Do I need spell penetration (if so, is it reasonable to go for it in PvE content?)? Do I need to be beyond the melee hit cap of 8%, or is the damage even related to the spell hit cap?
2. With 3.2 coming up, is it reasonable to aim for a +melee hit chance around 20% or is this just overshooting things? I guess +hit plays a bigger role in this build, the question I'm asking myself, however, is, if it's that important that I want it, even if I'm already at 10% hit or so.
1. all the bosses have some amount of resistances, these arent calculated through hit, but as you said it is spell penetration, dont gem for it, gemming for strength wil see a bigger increase, Frost strike and Scourge are considered as magic damage not mitigated by armour but resistances.
2. you havnt said wat spec you are going to try out, so i cant help there...