It really depends on how smart the girl is, many P4P refuse to have sex without a condom. Some also do very well financially, and quit when they have secured their future.
True, some are psychologically damaged, and descend into drug-taking and alcoholism. Having said that, your broad generalization does not apply to all bar girls and P4P's. Some are quite selective, and will only bonk punters that meet their criteria. A few will only go with men they consider to be potential husband material. Believe it or not, some enjoy sex, the cash is a bonus.
I've had sex with women in a range of ages here, although I can't say any were my age. I shower daily, and dress neatly. Not obese. I won't argue the ugly, which does not seem to matter to Thai women much anyway. I found being polite and considerate worked well for me.