Primary password reset
I use Sync on multiple computers for passwords. I have forgotten the Primary password on one of them. If I do a password reset on the one computer, does it affect the passwords stored on the Sync server, or maybe just the key4.db and logins.json folders on the computer being reset? I will not do a reset if the Sync'ed passwords could be affected, I'll just look them up on my phone. Thanks for your help!
Opaite Mbohovái (2)
Yes, it removes all your data from Sync server, including passwords.
You need a recovery key, see Reset your Mozilla account password with Recovery Keys.
Sorry, I misread the question.
You should be disconnected from Sync server before resetting primary password.