Individual character shopping is something I think would be good - then you can specialise toward a specific type of hero if you wanted to, also some in the group may get positive toward you whilst others negative, giving no change to the loyalty level - although in reality one of them may be desperate to return!
I am not that bothered by any additional back story for the characters, just come into my shop, buy stuff, go away again. If you survive and return, I may take more notice