DSM 7.2 Volume Encryption Key Confusion

When would one require the encrypted volume key or password? The key/ password is stored in DSM and the volume auto mounts on powering up of the unit.

Does performing a soft reset (one beep) to reset the admin password/ network settings require the volume key or password?

If one misplaced/ lost the volume encryption key, DSM allows one to download a new key and makes the original key no longer usable. Does this also make the original password unusable as well or is the original password still usable in cases where the key is not available?

Has anyone had a volume crash in a Synology? Would a volume repair require the key/ password?

This one is really silly, but while on the topic, if a drive in a RAID array fails, the rebuilding of the Pool with a new drive will not require the volume key/ password right?

I feel weird just asking these questions but I’m only used to full disk or folder encryptions.