I don’t think that Rumple knows about Belle. Whenever Regina told him that Belle was dead, he was feeling alot of emotion. He was depressed, angry, heartbroken, and on his guard, wondering what Regina would do next to try and steal his power. Regina IS a pretty good liar, so maybe he just decided to believe her. So he can get any chance of Belle coming back to him out of his mind. He really hurt Belle when he said “I care more about my powers then you” and she really hurt him whenever she called called him a coward. That probably brought back bad memories from before he was the dark one, and therefore he had a lot of things on his mind whenever Regina gave him a little visit. I think believing that Belle was dead would have been the easiest option, seeing that Regina isn’t really someone you would want to go up against. And retrieving Belle would have been hard, and he might not have known if it would be worth it.
As to the queen putting a spell on Rumplestiltskin, its possible, but not likely. Rumple is very smart, and i’m sure he would have noticed if a spell was cast on him. If the evil queen was prancing around my house telling me my loved one was dead and making tea like a pro, I would be keeping a watchful eye on her.