1) If I started feeling symptoms 10 hours after the oral sex (so, ~20 hours after the intercourse), what is the likelihood that I was shedding virus when we were intimate, even though I felt no symptoms at that time?
The individual shedding patterns of people are so variable, it is difficult to say but it is certainly possible that you were shedding virus 20 hours before an outbreak.
2) If I was shedding virus while we were intimate, despite being on valacyclovir and using a condom, what is his risk of being infected?
I think the risk are really quite low actually, with both of those “defenses” going on. Even with an outbreak, the medicine would also reduce the amount of virus present.
3) Maybe the most likely transmission is from the oral sex, genital to oral, since we didn’t use any physical barrier method of protection then, and the oral sex came after the triggering event (the friction-heavy intercourse with condom), and the oral sex occurred only 10 hours before I started feeling symptoms. Can a person get HSV-2 orally, and would he have recurrences in his mouth? Would the oubreaks stay oral or can they manifest genitally?
Yes, a person can get HSV 2 orally, though not common, and if that happened, he would be virtually vaccinated against genital infection. They would stay oral only and he would have rare recurrences.
4) If he does contract HSV-2 from me, either genital or oral, when would he be likely to experience symptoms (if at all)? Within a few days? A couple of weeks? I want to know when I can start breathing normally again… I know that he can get tested, but that would have to wait some weeks to be accurate
IF he was going to experience symptoms, it would likely be within 2-10 days of the encounter you describe.
In my opinion, he should be tested now if he has not already been tested. He may also be infected and not know it and then you wouldn’t have anything to worry about, right? Maybe he has already been tested and you just didn’t mention it but that is always my first recommendation in these situations.