I guess I'm going to be the Debbie Downer of the group. People involved in "escort" services are almost always engaging in prostitution. The reality of the world of prostitution is often one of drug and alcohol addiction. You don't mention if he, or you, uses drugs now or in the past. He clearly is at least bisexual so that is one issue you know about and need to decide whether that matters or not. I don't believe the rationale that he didn't really do any escort stuff because he never got past the texting/payment stage. That sounds like he's telling you just enough truth to cover what you found out on your own but keeps him from going any further. Have you considered paying to have a criminal history check done on him? I think that would be a reasonable step to take. Frankly I think there are too many warning signs for you to ignore.
