Try The Noble's Handbook by Rodney H. Thompson, aka Moridin. It's a part of Green Ronin's Master Class series (which include my favorite: Psychic's Handbook & Cavalier's Handbook).
Check out the Noble Class from Guardians of Order's A Game of Thrones RPG - it's available on agot.guardiansorder.com as a free preview . I like it a lot.
What about that: You give up sneak attack (I guess that's what seems most out of the question here), and instead get bonus feats at these levels (all related to social interaction and the like - persuasive, skill focus, open minded....) and change the class skill list (no sleight of hand, open lock, disable divice, but knowledge (nobility, history, local) and so on).
Talk to your DM, he may have more ideas and tweaks for this.