Is there a possibility to make an affinity clan boss focus a champion of the opposite affinity (for example making a magic affinity clan boss focus a force affinity champion) right from the beginning?
I really don't think so, but it might if the champ is on the lead position and has insanely low HP. I gotta ask though, what champ/ team comp did you have in mind when you were thinking about this?
I wondered if it is possible to make a Skullcrusher take the stun if there are spirit affinity champs on the same team against a magic affinity clan boss.
Basically no. CB will always target weak affinity first in basically every situation. Even if they have counter attack buffs up, which he would usually avoid when he is still in void mode.