How to become a better bunny owner?

Duncan. I love the name, perfect for a bunny. Go to House Rabbit Society; site has a q/a section, has help for every breed of rabbit and every rabbit problem. Also, About.com:exotic pets has much help. I don't know about the flea problem, but House Rabbit Society can help you. You really want to be a good rabbit parent/friend/owner, certainly I can tell from your plea about correct care of Duncan. We had a house bunny, a loppy, for many years, and he was an absolutely glorious pet, everything we wanted in a pet. And Duncan can be as well, give it time, attention, patience...best luck.