as stated elsewhere in the Forum, the Support Team is doing their best to reply, but it is unfortunately not possible to reply to every enquiry in a timely manner these days. Sorry.
If you own Cubase or Cubase Artist, you can just buy the upgrade to Pro, yes.
As Elektrobolt wrote, you don't need any further installation, as Padshop and Padshop Pro are the same installation, the license unlocks further functionality.
There is no stand-alone version of Padshop.