No, because it is already enchanted.
The items of clothing from the thieves guild is the armour you get from them when you become a full member of the guild
Well if you are referring to the armor I know it just powers up your current thieves guild armor (one piece of it) to make it stronger. If you are talking about the trainers they have in the thieves' guild I know there is archery, lock-picking, and sneak. I am also pretty sure they have pick-pocketing and light armor.
Thieves Guild missions.
The Guild of Thieves was created in 1987.
The Guild of Thieves happened in 1987.
Once you've been initiated into the thieves guild(taking care of buisness quest), you go to the ragged flagon in the ratways in riften and see tonilia (or tanilia cant remember ;)) and she'll set you up with your thieves guild armor
I would enchant it to mage because all of its attacks are magical.
In TES Oblivion, the Thieves Guild is led by a figure known as The Gray Fox. This isn't one person, but rather a series of thieves changing roles since the beginning of the Thieves Guild.
The only armour that is close to the thieves guild is the actual thieves guild armour which you get when you become a full member of the guild or there is the nightingale armour which you get when you become a nightingale priest
You have to complete the thieves guild missions including vex's and delvins additional jobs, then go and find brinjolf and ask him about becoming the guild leader
Riften.
No, you can kill people freely at other times, just as long as they are not also part of the Thieves Guild faction.