Is there a function to change an actors name using papyrus? I would like to spawn an actor and then be able to have a script change its name.

There isn't, but I believe you can temporarily change an actor's name by making a quest alias point to them, and specifying the new name in the alias. Aliases can be manipulated via script, so that could let you do what you want to do.

Cipscis

Hm, not really an ideal way but I might be able to use this. I'm not sure quite sure if it will work though, I can see some issues.