This I will not dispute. Again you are right that 80% of adults have HSV-1, but only about 20% have HSV-2 and you can have both. Chlamydia, and gonorrhea infections of the throat are symptom-less and require a throat swab that most people do not get. Most people with such an infection do not know it. Standard STD tests do not test for an infection of the throat.
Most everything you have said is true. BBBJ are not low risk just lower risk. DATY is even safer. For both parties.
By the way oral sex is a major way syphilis is spread. It spreads quite readily by that medium.