Well not to get down on you but.....
You have made clear you won't move in with him. It's marriage or no dice.
He must propose to you.
You have "an idealized" idea of marriage.
I'd say you are both a bit set in your ways unable to give ground no? I have a few friends of mine that always feel a relationship has to "be going somewhere" in order for it to be good. They assure me it's a good relationship now...but want it to be "going somewhere". This always confuses me a bit. If you are enjoying your time together, love each other, who gives a shite?
You seem to care way too much how other see you. You want a big wedding. You won't live in sin without marriage. You care how others look at your "odd" relationship with him. SCREW THEM. It's your life and your relationship. If you love each other and it's good...so be it.
Maybe he's afraid that by marrying you it will turn into what his last marriage did. A great, passionate friendship that fizzled out once the rigors of day to day life reared their ugly head.
You make the first step. If you move in and everything goes ok...then in two years get hitched. I honestly feel women have been sold the biggest bill of goods by the wedding industry that somehow their day will be perfect and all issues will melt away. Blech! Huge magazines devoted to "the ideal wedding".
I have a nagging feeling you haven't been 100% forthright in communicating with him. The old "he should know how I feel" without actually spelling it out for him usually applies here. No MEN just don't get it sometimes unless you explain it, paint a picture, AND ask them to repeat it to you. I guess maybe I just get a little confused when the choices come down to...we either get married or break up. Which is usually shortly followed up by...we either have kids or get divorced. Maybe cause I'm a man I just don't get it.
Evil gets off soapbox....heads to bed.