Wearing armor does mean that you won't benefit from the mage armor perk in the alteration tree, if you're investing in that, but if you wanna wear armor you can do that for sure. It really doesn't make that huge a difference either way honestly, and I wouldn't stress too much over what you do or don't put perks in. You can max every skill in the game if you want, and if you've got the patience for it you can get every perk as well.

All robes in skyrim are clothing, which have no defense by definition. Only light and heavy armor can have a defense rating. In your case I wouldn't bother with smithing since it doesn't sound like you're really gonna be wearing armor or even using weapons all that much. I'd probably go with enchanting myself since you can easily buy or find most potions you really need and as a mage having good enchants on your robes makes a huge difference, especially if you're not gonna exploit the alchemy/enchanting loop (which I personally wouldn't suggest doing).

I was interested in this even before I saw it was by DarkFox127, that fact was enough to make it an instant download. His stuff is always really well put together.

Probably a lot like the person who said No Rain by Blind Melon.

All Star by Smash Mouth.

Mist Fall Keep is a bit of a less popular option but personally I think it deserves way more attention than it's gotten. It's not only a really nice looking and fully featured player home, but it also offers displays for practically every item in the vanilla game and the AE CC content. It makes for a really great option for someone like me who loves collecting stuff but has done the LOTD quests a few too many times.

I've used Valhalla Combat for a few playthroughs now and found it to work really well with MCO, personally. I've also used Blade and Blunt in the past, but haven't tried out the newer versions with MCO yet so I can't say how well it works.