Just been over your posts OP and i can't tell - have you actually discussed marriage directly with him at any point? Just in conversation. This should tell you 99% of what you need to know about how he feels, and how likely you are to be receiving a proposal anytime soon.
DH and i discussed marriage in general, our feelings towards it as a concept, if you like, and what we observed about other peoples relationships; married or not, way before our relationship was old enough to even think about marriage for us.
With DH and I, since you've asked for examples, - I've been married before, but was always open about the fact that i was not anti-marriage at all, just because i'd got a failed one under my belt. DH was adamant from 'day 1', him he would never marry!
He is younger than me, i have 3DCs, he has none. I love him more than the idea of marriage. After 2 years 'going out' we moved in together. I think he had been viewing marriage as some sort of 'man trap' through his twenties, and early 30s. I had no expectations from him, he knew that. I never thought he'd propose. I guess he kind of mellowed, felt settled and happy. Three years after we moved in together he suddenly proposed! I've never quizzed him too hard about what changed in him.
His proposal was a lovely surprise. Not entirely out of the blue however - a month before he had casually asked me one evening: 'would you say yes, do you think, if i asked you to marry me'. 

