I would sugest that you look at the Capacity License (which includes VMware capability but gives more flexibility for the odd physical system etc and in the long term may be the better choice). Some info on the capacity licensing calcualations available here http://www.veritas.com/docs/000025717
With regards our virtual agent licensing I would say that the VMware/Virtual agent license on it's own would not be cost effective as you would need a number of application and database agent licences as well as 4 virtual agent licenses (covering each ESXi host) - you could look at the V-Ray Edition (which you would also need 4 of, where the exact Tier you would need to purchase depends in the CPU count in your ESXi hosts.)
As long as you stay with the Capacity or V-Ray editions
1) You would install agent software inside the windows machines but do vitual agent backups and not need extra agent licenses
2) Linux VMs do not support GRT, so RALUS agent backups would be needed and the Capacity Edition would be the better choice to cover this. You should also check our SCL to cnfirm support of the Linux versions you are using.
3) The windows agent software will need installing inside the SQL VMs but no extra licenses will be needed. Note I am talking about MSSQL, MySQL is not officially supported although if you can dump the MySQL database we can backup the result of the dump (and a complete VM containing MySQL will be protected for a DR recovery, possibly in a crash consistent state against MySQL)
4) The Windows agent software will need installing on the DCs but no further licenses are needed.
5) I am not sure we support Oracle Backup inside a VM (you would need to check this as you might need ot run an agent based backup of Oracle and then the Capacity Edition becomes the best choice)
6) The virtual agent process (irrespective of exact licening model) does have some environments it cannot fully protect (GRT of Exchange DAG, GRT of Linux etc) but can protect and allow individual item restores (using GRT) of most of your environment - so not quite take care of eveything but get close.
If you do not go with Capacity or V-Ray editions then the answers to 1, 2, 3 and 4 (and possibly 6) change in terms of required licenses as you will need various Application and Database Licenses and maybe RALUS licenses covering some of your 70 odd machines
