Yeah, work on grammar and spelling before you take the MCAT.
Part 135 may have SIDA restrictions depending on where they operate. Part 91 can basically hire whoever they want, like others have said it comes down to who you know, personality, and yes even looks. If you're flying the boss to a resort town or european city with legendary nightlife and staying for a week, you want someone to party with.
Your criminal history doesn't matter unless it offends the boss, insurance has stipulations, or it will create customs problems on international flights. This guy is not going to be flying to canada, that's for sure.