backup proxmox configuration (database) and vm templates

Hi,

we have a question about backup configuration of proxmox config and his database. is it a sql lite db or what we must backup to have a backup of proxmoxsystem?

Our 2nd question is, has proxmox 64 bit templates or only 32 bit templates in download area?

And the 3rd question is, what for permissions we must set for a user or a group, than the user can reinstall or install a other image on her own machine? As admin i haven´t found this option, too...

regards