I don't think so. I think he's just being prudent. When you blur the lines between business and personal lives, you need to set boundaries. He wants to treat the loan he gave you as a business deal and nothing else. It's not a bad idea to have it in writing.
A woman promises to love and be with a man forever, the man wants a ptenup. Does that mean he doesn't love, or trust her? Shit happens! Even with the best of intentions. Maybe he been taken before, and wants to play it safe. Life's a gamble!
It means he is looking after his assets. There is nothing wrong with that. Everybody thinks their relationship will last for ever, but in reality, 50% of marriages break up, and thats if you manage to get to the isle, so you need to protect yourself. Its fair what he did. It has nothing to do with trust.
Yes. Just because he's your boyfriend doesn't mean he has to trust you. Couples break up. You might break up in 4 months and then yeah, you're still gonna owe him money. Doesn't matter if your feelings are hurt.