Further, and more importantly, even most unprotected exposures do not lead to transmission of infection and condom use reduces this greatly.
In your case, oral sex is very, very low risk for
HIV- the estimated risk of
HIV from oral sex with an infected partner is, on average, less than 1 infection in 10,000 exposures and there are no proven cases in which a man has gotten HIV from receiving oral sex- none!
As for your specific questions:
1.