A few comments from a salon owner...Most states do require a license which means 200-500 hours of training. My salon charges $25-45 dollars for nail services. You get 50% commission plus tips, generally $3-7 dollars per service. Each nail appointment can take 20 min to an hour...do the math. The faster you are the more money you'll make.
As for the sexuality issue...if you're worried about what your "friends" or clients think about your bedroom behaviour, you aren't mature enough to work as Nail Technician or PC Technician for that matter. Your chosen profession is not a dating service. If you are planning to use it as such, hire a good lawyer.