Hi:
HP only supports their consumer model notebooks for the current Windows standard operating system in effect at the time of production, which is Windows 8 today.
They will never release any drivers for either of the operating systems you want to install.
It is highly unlikely you will be able to install either operating system you want to install.
If you install Windows Server 2008 R2, you may be able to use windows 7 x 64 drivers from this related model.
DO NOT USE ANY OF THE BIOS FILES
Even HP business notebooks do not offer support or drivers for those operating systems.
I do not know the answer to your 3rd question.