I was going to comment but Austerus hits the main points.

Add "Are you trustworthy?" Do you take care of your possessions or let them fall apart from neglect or disuse. Will you treat your submissive the way you would wish to be treated were you in her/his position? (And I'm not talking about how you play. I'm talking about how you think about them, how you interact with them. Do you have friends and do they like you? That's a good bellweather.)

BTW, if you're really being introspective, answer your questions truthfully. If you lie to yourself, you have no hope of fixing your own issues, flaws, or foibles. Nor are you trustworthy if you can't be truthful even to yourself.