The Guild of Thieves was created in 1987.
The Guild of Thieves happened in 1987.
The items of clothing from the thieves guild is the armour you get from them when you become a full member of the guild
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
No, you can kill people freely at other times, just as long as they are not also part of the Thieves Guild faction.
Not 100% sure about general merchants but I know that all Thieves Guild members sell them. Just join the thieves guild.
Yes, you can.
Yes
The Thieves Guild/Den is located in the Waterfront District of the Imperial City.
No, because it is already enchanted.