Re: Living together before marriage. Yay or nay?
Honestly, it doesn't sound like he's interested in making any real commitment. I wouldn't do it because I think it would lead you do heartbreak.
DH and I were engaged when I moved him in with me. Actually he had been spending most of his nights at my apartment anyway, and was rarely at his house, but we made it official and put him on the lease about 6 months before we actually got married (we had a 15 month engagement.) It was more about convenience than anything, because we were already engaged, the vast majority of the wedding was already put together.
I would not want my daughter to move in with someone just because they felt it was the next step or because they wanted to avoid marriage. I firmly believe in but if someone doesn't want to get married, I am fine with that too. I think though that if you want a separate life from your girlfriend, then you just keep it separate. I think long term cohabitation without a commitment rarely if ever turns out well.