This is especially true if combat becomes a deadlier affair, as I'd prefer. Note that I am not promoting the removal of more skills in general, quite the contrary, but this isn't the place to get into my own skill set or the ones relevant to armor. When it comes to removing unnecessary clutter, though, I see little need for armor skills. With deadlier combat, fights are more about not getting hit, than about how many times you can withstand being repeatedly stabbed in the chest. Armor should be about preventing damage, not reducing it; what kind of crappy plate gets punctured by a blade every single time and just makes you less wounded? This would further deflate armor skills because protection would be less about defense scores. You can further expand this for extra variety. Plate might be highly resistant to lighter weapons like daggers, leather doesn't impede dodging skills, ebony is hard and damages lesser materials, chainmail is strong against slashing but weaker against piercing, etc. While some armor would be better than others, the character type and situation would greatly change what's ideal, instead of every character winding up with the same "best" equipment and looking identical to each other.
A thought regarding item stacking. Say you've got all the squares for equipment slots and such, and can equip two things to each (or most): one armor item, and one non-armor item. Shirt and briastplate, gloves and gauntlets, pants and greaves, head accessory and helmet, etcetera. You have the picture icon for the item in the slot, and in the top right, a shrunken down thumbnail version of the other item in that slot. You can click the smaller image to swap them, giving the larger one priority and wearing it on top of the other. Each slot could be thus fiddled with separately and you could mix and match as you please. Items that warrant more options could put them in another corner; hood up/down, helmet open/closed. Robes would probably need their own slot instead of just being a torso item, since they cover everything. Equipping a robe would add an extra priority option to each relevant slot, for if you want to mix it up like having the chest armor over the robe but the lower robe covering your legs. The robe slot itself could have capacity for two items, a robe that has the previous options, and a secondary item that always goes over everything, like a cloak or cape. Hopefully I explained that well enough to make a mental image...not every item could have a priority swap, of course, but it would be a system that lets you pretty easily customize armor and clothing appearance. With equipment based on its individual abilities instead of a universal defense stat, it would also give you further freedom instead of everyone ending up with the same all daedric or mishmash of artifacts.