I basically want some kind of license agreement
How should I go about that? I'm broke and I can't really hire a lawyer to write some crazy legal stuff for me.
Then you can't proceed at the moment. Just save money until you can afford the lawyer. I assume you're creating this engine as a moneymaker (a business venture). If you're broke and can't afford an attorney right now, you can't start your business venture right now. Wait until you can. Have you tried at least contacting some game attorneys? Maybe it doesn't cost as much as you think.