1) If a man had condom protected intercourse and condom protected fellatio with several different female sex workers on several different occasions over 5 years ago (and has remained celibate since) and has never had symptoms, what are the chances he did contract herpes, but has remained asymptomatic?
Very low, indeed.
2) If he did contract herpes but never had symptoms, what are the chances of spreading it to a partner through unprotected sex?
well, that depends totally upon the type and the HSV status of the current partner. We no data on HSV 2 transmission but if someone is infected with HSV 2 and is asymptomatic, they shed virus on about 10 out of 100 days and the transmission rate is about 10% per year having unprotected sex about twice per week
3) If he would like to get tested to be extra sure, what would be the most accurate test to take?
the herpes western blot from the University of Washington