People with genital HSV1 shed an average of 10 to15 days a year. Antivirals would probably halve this. That's is not a great gain for daily usage.
If your partner already has HSV1 then that is the best protection you can have against transmission.
No, it is for the suppression purposes only
I think you will end medical advice on this one.
Antiviral will often not be needed for HSV1 infections. Are you suffering frequent outbreaks, is the infection recent?