In Skyrim only 2 out of 4 enchantments are shown in Active Effects

Making it "easier to cast" is relatively straightforward - it reduces the Magicka cost of the spell, meaning you can cast them more often.

This is similar to how things worked in Oblivion. (I'd link you to the UESP page documenting this, but the Site's still getting hit pretty hard from all the Skyrim traffic)

Each spell has a "base cost", which is modified by the following formula:

spell cost = base cost * skill multiplier * perk multiplier * equipment multiplier * dual cast multiplier
skill multiplier = 1 - (skill/400) ^ 0.65

This means that at 100 skill, spells cost 60% of the base cast (further modified by perks and equipment).

This isn't combat related, but as Affe has pointed out below, increasing your magic skills is required to buy high-end spells from vendors.

Clothing is much faster than any armor. Weapons sheathed makes you run faster, and sneak rolling is actually slower than sprinting in light armor. I'm not sure about heavy armor, but I believe rolling is always the same speed. I believe carry weight has a small effect on move speed, so it might be fastest after selling off... I mean DONATING your Dwemer artifacts to a... ahem... MUSEUM.