I wonder how obvious it is to the various villains of the DCU how susceptible to the persons-he-loves-being-targets Batman is. Brother Eye was aware of it, but the rest?
I'd like to note that just because Batman won't kill whoever killed/hurt one of his loved ones - because this ain't an alternate Earth or an Elseworlds - doesn't mean that villains would be less afraid of him. After all, fear's irrational. Otherwise everyone would be a lot more scared of Superman than Batman, if we went by the criteri of the things they could do to you.
Another side note: I find it fascinating that all of the people Bruce loves, he's met through Batman, with the exception of Alfred and Leslie, and all or almost all of them are heroes themselves. He's definitely aware of the risk people close to him could be in, so the only people he lets get close are people who have the best chances at getting out of trouble.
For Jim, I think it could've gone both ways. You're right, given the events of NML he could have done it, but given his character it would also, I think, have made sense for his character not to do it.