I dunno 'bout the whole toggle view in third person, because theres about 30 or so helmets for each class (light or heavy) but, toggle helmet view in first person, where you actually had to look through the eye slits of the helemt would be cool, impractical but cool none the less.
I wish they brought the character view back to the inventory menu and that you could put different pieces of clothin/armor on different parts of your character like, say I have the Alik'r hood and an Iron helmet, i could wear the Iron helmet and wrap the Alik'r hood around my neck (because it's a scarf) or if i wanted to mount my claymore on my hip instead of my back so it would drag the ground when I walk... THAT would be AMAZING!
In Morrowind, robes were worn over armor.
Now, we not only don't have separate leggings but can only wear one ring.
At the rate things are going, it'll be TES VII where armor comes as just two pieces. The helmet and the rest of the body and even then there won't be an option to toggle the show of the helm.
Something I might do with the CK (and a 3D graphics program) is to make necklaces that pair up with the armors (Elven Pendant, Daedric Amulet, etc.). These will be classified as light or heavy armor pieces respectively but offer no armor rating of their own. They will be added to the sets as an alternative head piece. This will give you the bonus of the perks. Then it's a matter of making necklaces use the head slot, and allow rings to take advantage of the now vacant neck slot so two can be worn at once.