Ok can i enchant the skaal gear for improved destruction and magic regen
I want it for my nord mage-understanding it cant be improved and not best for powergaming

On light armors if you cast say ebony alteration and it shows that your character is glowing it it really working or is this a game flaw?

Sure, I don't see why not. Enchantments are only restricted by whether the item is a chest-piece, boots, headgear, gloves etc. You can put nearly any type of enchantment on a chest-piece like the Skaal coat, while the hat should also accept the two enchantments you mention.

What do you mean by 'ebony alteration'? The 'Ebony Flesh' spell? If yes, then casting it does cover your character in a shiny glow for the duration of the spell. To check if it's working, open your menu and go to inventory, then check 'Armor Rating'. If the number increased, it worked.