No, we don't live together.
I am thinking of living together as an alternative to marriage, but I haven't brought it up with him. Now, I am questioning whether living together is a good thing. I don't want to feel not good enough to marry. But, then again, given the strength of my finances, I would actually have more to lose than he does if we got married and then divorced. It just shows that he's not a gold digger because if he were, he would really want to marry me.
I disagree that if he were a gold digger that he would marry you.
If he's a gold digger he could set himself up so that you, as the major earner with the most assets pay most of the bills and provide your assets, like your home, as asset available to him.
Then he saves his money.
In many states, even without marriage, there is palimony, etc. He could sue you for support and for a portion of your assets. Do you live in a state that allows for this?
He says that he wants to be with you for a long time. He's not committing to being with you forever. A long time can me a year, two years, until he meets the woman of his dreams, or forever. You have no idea.
If you stay with him, keep in mind that he has made no commitment to you. My experience with men who do this is that they are still on the lookout for the next, better woman (whatever he considers better).