At this point, I don't think the trade value of Bradley is relevant. His value is basically non-existent, so it is not going to be hurt at all by playing him more...but it also is not going to be helped at all unless he plays significantly better.
I think Doc needs to be doing what is best for the team on the floor, completely ignoring trade implications. I think Moore will ultimately take over, but if he is not ready yet, fine, let Bradley keep the spot warm while he learns the system...and who knows, maybe he will surprise us (I doubt it).