I was on my phone earlier, but I wanted to come back and post a bit more now that I'm on a computer. You've gotten some great insight here. And as another person said, even without him being an A, I'd say run. Sure, some guys are "just like that." And they're losers. They don't have to be addicts to be crappy guys. And crappy guys make crappy husbands. He isn't going to magically change because you get married. If anything, those cracks in your relationship are going to be magnified.
Also, creditors will start coming after YOU to make good on HIS debts. That's fun, lemme tell ya. I didn't know until I married my ex-husband, that he owed the government $40,000 from a contract bonus he received and then failed to fulfill the contract. I had earmarked our tax refund for other things that needed taking care of, and it all got eaten by his debts. I was LIVID. Then the whole thing started unraveling. He was so in debt and I was on the hook for all of it because I was his wife. Are you ready for that?