I think light armor (which is basically unarmored) should have no armor benefits and spell resist, like how it was in previous TES titles. I do think that light armor should instead get stronger Wards (magic shields) such as annulment, and daedric ward etc. As for heavy armor i think it should have increased spell resist and more armor because heavy plated armor is usually used for defense. I also think heavy armor should get a perk where it decreases the amount of damage critical hits do, I seen that in another thread about heavy armor and thought that would be a good idea.