I was not aware Quickstart Edition was still available, when it was available as far as I know it was ONLY sold bundled with Hardware (servers and/or tape drives) - as such I have a concern you are reading old documentaion - please review this: https://www.veritas.com/docs/000116657
In your scenarios you do not state if the Backup Server will be it's own server or on one of the ones you mention (which makes a big difference to the answer) - you also do not mention what type(s) of storage you intend to backup to (which could also need specific licenses so changes the answer. In reality the more complicated the requirements the more it should be pushing you to Capacity Edition as that includes the agent and options as it is charged on multiples of 1TB against 1 full backup of everything, (Note you should initially buy capacity to cover current and planned growth over a reasonable timescale)
To try to help if you still want to try and assemble an a-la-carte set of licenses:
- If the backup server is one of the existing servers then you are allowed to backup the file system and system state of that same server against the Backup Exec Server license itself
- if a remote server runs a supported database technology (SQL, Exchange etc) then the Application & Database Agent license also allows you to backup the system state and file system on that remote server
- best practice (due to ease of DR) to backup virtul machines is to back then up using virtual agents however unless you get the V-Ray edition, virtual agent licensing itself does not include GRT against any databases inside virtual machines you will then need a virtual agent license (for the host) and an Application & DB license for the VM for that scenario
- if you only buy V-Ray to cover Hyper-V virtual machines then any physical servers that need backing up (excepting the Hyper-V host) will still need agent licenses
- if you have 2 or more tape drives in a tape library you need LEO licenses
- if you want to use Deduplication, you need a deduplication license
