This may sound like a stupid question, but I want my mage to wear the mask of morokei. My mage typically uses robes with mage armor and I want to know if the mask, since it's considered light armor, will negate the perk and render it useless? or if there was some kind of exception. It just seems like a waste if mages can't wear it.

It will negate the skin perk. I opted for enchanted robes, and eleven accessories.

The only armour that can be worn without losing the mage armour perks, and then due to a glitch I presume, is fine armguards, and you can only obtain them from Jarls, or the Thane Bryling, IIRC.

Can I disenchant/re-enchant with high enough enchanting? that would solve the problem.

The masks cannot be enchanted.

Also, IIRC, shields also don't count in regards to Mage Armor perk.