To answer your first question... It's not wrong at all that you don't let him go bareback! Stick to your guns! I know it can be difficult to resist giving in to pressure to regular clients who give us so much business, but I'd rather not have this man's business if he was going to give me a gross disease or make my heart hit the floor every time he called to arrange an appointment because I'd be dreading bareback with him. I don't believe someone producing an STD status card is any proof they are clear of STDs, as they could have had unprotected sex and caught something between getting tested and getting the results and that card.
Second question - Nope, none at all. I will block someone even if they request bareback. My thinking behind that is "If you ask for something you really want and are refused, you might try to get it anyway..." and bareback is one of the few things I can refuse to do that they could sneakily try to do anyway, by pulling the condom off in doggy or ripping it or something.
If you don't want to offer bareback, then don't, and good on you for saying no to keep yourself sane. He should go see a lady that has made the choice to go bareback and is happy about it, instead of seeing someone who does not want to do it at all. He pays for your time, and has the pleasure of doing things with you that you like in that time - he is not entitled to jackshit as long as you advertise honestly, and I'm sure you do indeed.