Hello new here. I'm just wondering if anyone knows of a place you can buy or sell items when your a full vampire. Seems like everyone i walk into they all run away. Thanks.

hard as a full vampire, usually stock up on my loot until I run out of repair-hammers,feed and walk around inside (no wait/rest) close by in the market district,for example inside the feedbag or the merchant inn,make a rush just after the shops opens,preferably one that buys everything,or as much as possible,resupply with more repair-hammers,ingredients,potions and whatever,and back to my living quarters.

as a partial vampire a charm spell might work combined with decent personality,tough as a full vampire but as 2/4 or 3/4 it might work with help from charm-spells,fortify personality and such.
there is a reason those hammers get bought in large quantities,the rest can be looted easy but to get enough hammers is my biggest problem.

Do you happen to know if you can use your fence as a thieves guild member?

As a vampire? Don′t think so as they recognize you as one too, same as any merchant.

By the way, welcome to the forums and have a complimentary http://images.uesp.net//c/c4/Fishystick.jpg