I am indecisive about the idea of marriage with my 5yr long distance boyfriend...opinion?

I have been with my boyfriend for 5 yrs. Im 26 and he's 25. We live an 1 H 1/2 apart and see each other at least once a week, sometimes more if possible. We both love each other. But I have reservations about marriage. There are a couple issues that concern me (his smoking, and binge drinking with his friends on wkends). I want him to stop these harmful lifestyle habits for his sake and for mine if we marry/ kids. I want us to live together even just for a short while so that we can weed out any other issues we could have if we married. He says he doesn't want to move in with me bc it means we'd be renting and he wants to stay @ his parents to save $$ for 2 yrs so he can buy a house for us to live. Waiting till I'm 28 or older to move in with him seems scary if we find out we shouldn't marry. We both love each other but moving fwd in the relationship has become difficult when we're not on the same page. Should I follow my heart and stay with him or my head and move on?