1. How likely is it that this was an initial infection?
Sounds from the duration of symptoms that it was a new infection. Also HSV 2 orally rarely recurs so I doubt it was a recurrence.
2. Is it reasonable to conclude that I do not have genital hsv-2 because I did not get genital lesions?
Reasonable yes, absolutely certain, no.
3. How should I think about the risk of spreading hsv-2 to others? I won’t put my mouth on someone if I have open sores — but what about now, where my sores have been closed for 4+ weeks but I still have some redness/sensations there? Am I still shedding virus, or is it just normal skin-healing? Assuming my chin clears up more, is the risk of spreading it very small because it’s oral hsv-2 (compared to oral hsv-1 or genital hsv-2)? Is risk different for kissing compared to oral sex?
HSV 2 oral infection is a rarity to start with but recurrences and viral shedding are also very rare. I think transmission to another person, either kissing or giving oral sex is highly unlikely. I would never say never about this, however.
4. I intend to continue to have a variety of sexual partners. Is there any clinical indication for using Valtrex to reduce asymptomatic spread of hsv-2 for oral infections, or is that overkill?
I do not think it is overkill, at least for the first 6 months or so. Because oral HSV 2 is rare, I don’t think we have good guidance on how much this will reduce transmission to another person.