A lot of people simply enjoy a power play exchange in the bedroom. Adding an element of tension or rough play into sex can be extremely erotic and very pleasurable. Often the people who like to play rough in the bedroom are completely different in other aspects of the relationship. I don't think anything is wrong with rough sex as long as you are willing and trust him. They key is that you are OK with it. Don't do something you're NOT ok with for his benefit. But I don't think it's inherently unhealthy. Look into some FAQ on BDSM and Dominant/Submissive relationships...
(Here's one, but I'd suggest googling some others. There is also a book called Different Loving you can look up on Amazon.com, it provides a good overview of d/s relationships.)
It's a good idea to have a 'safe word.' Meaning, a word that you say that will make him understand you want him to stop. Safe words should not be words like "no" or "stop" since often saying no and stop is part of a forced sex roll play, which you indicated he was into. I would pick something completely out of place that cannot be mistaken.
If you want to talk more about it, feel free to email me. If not, have fun and play safe!