Intelligence also effects damage (up to 150% max) and hit chance. It is useful for offensive spells to be above 100% as enemies' resistance lower your hit chance.
I don't know. I think not.
The hit stance doesn't influence skills, since skills have 100% hit. But as far as status effect are concerned, same answer as 2. The power stance does influence skill damage (and skill still have 100% hit chance).
