I can't speak to #1.
Regarding #2, before I delete accounts, I use Drive Transfer to move all of their files to a special user set aside for that purpose. A subfolder named
old...@domain.com old files will be created as a subfolder in the destination drive.
gam user <source email> transfer drive <destination email>
I then suspend the users and move them to a special OU:
gam update user <user> ou RemovedUsers suspended "on"
-SD