Well, the first rule of thumb is to not marry someone until you are confident you are compatible. I know this is easier said than done, especially for people who tend to live in the moment. With that out of the way, your current situation is very complicated. I will make it easy and just answer the question, if my SO was running from the law and expecting me to financially support them, absolutely I would get a divorce. Someone who has all of these traits is an irresponsible person, in my experience irresponsible people very rarely change. The person that you have described does not love you, they do not care for your well being, they care for themselves and what they can get.