I was at RMC from Sept. 2002 to May 2006. Whatever what he does at RMC (unless he's a UTPNCM, which is a person with previous time in the military, doesn't seem to be the case of your boyfriend) doesn't matter on his living conditions. I don't think he'll be allowed to leave the campus for the first 2 years (unless you are married or common law, in which case I would think he could live out in 2nd year only).
In 4th year, me and my spouse decided to live together in Kingston. She isn't in the military. We lived in the PMQ's on the base and no, the condition of the PMQ's isn't bad at all (in fact, it was pretty good). We lived in the appartment (3 bedrooms) and looking back, we should have lived in a small house (it's approximately the same price, if you take into account hydro and gas). Since I was the only one working, they couldn't take more than 25% of my gross salary for the shelter charge. On top of that, I had to pay for utilities (160$ for heating, which is HUGE) plus hydro (50$ per month approx). If I had taken a house, it would have been 25% of my gross salary plus whatever I take in heating and hydro.
If you have any questions, feel free to ask me in PM or here.
Max