wizards, nuking & aggro, raiding.

[Daldaen]

Concussion drops aggro on a resist.

All spells have a raw Hate Value associated with them. These values are front loaded (DoTs being exceptions). Meaning on the casting, that value is added to your hate total.

That warrior who burned mallets on VS, whom is magic immune, had 5/5 Resists and still gained aggro on them (though it is very likely he didn't use 5 or burned charges out of line of sight if 2 casts got you aggro). Point being resists on spells generate aggro too. The same amount as the spell landing does.

Same thing is applied to Concussion. Resists will still apply the negative hate value to your total dropping you.

This is classic code and still the way it works on live. The developers didn't fully understand this though, see Cinder Jolt. They felt it necessary to make a different resist jolt spell because they didn't understand their own aggro code.

The rest of your questions... Sunstrike trash at like 50%. Don't group on a wizard that sounds awful. If you can't Bane a mob and you can't Lure of Ice (ice dragons and eashen), you're better off just swapping to another character.