I agree with the advice given here. In my business, jobs come up all the time that are undesirable to say the least. And every time my gut has told me not to take on a job and I did it anyways, I lived to regret it. Usually immediately.
An example would be some windows/French doors that I renovated and refinished last year. They were on an historical apartment building in Hollywood that belongs to an acquaintance. The initial job went fine and customer was happy, i got paid with no drama. A short time later, he called me to do some small "handyman" type stuff that is not what I normally do. It happened more than once, first it was a minor plumbing issue then some other repair. I tried to brush him off but he practically begged so I drove over after work, (during L.A. rush hour), and did it both times. I will admit that part of the reason is that he had talked about other possible jobs with a prominent designer he knew, etc., and I wanted to stay in his good graces. To make a long story long, I was never paid for the "extras" I did for this jerk and had to go through an increasingly unpleasant set of demands for it before giving up and writing him off. BTW, in my experience when people talk a big game about all of the work they will send you, it never happens. It's almost like it's part of their game to get something for nothing.
My uncle is a banker, as was my GF. Both are/were well-regarded in their communities, very charitable, etc... My uncle once told me that his dad had a saying, "don't loan money to people you don't like". He would never have discriminated in a bigoted way, (even back in the 1930s when it was probably legal), he simply meant "don't do business with jerks. You'll be sorry."
