1. Your steps look fine based on the workflow I did in the Spring to do a very similar migration. My server is a mix of Pharos and non-Pharos queues so I had to work with the Windows Print Migration tools.
2. I used the Print Migration Tool since I had a mix of Pharos and non-Pharos queues. If you have all Pharos queues there nothing wrong with your workflow.
3. We installed the Printer Role directly from Windows and then let the Pharos installer do what it wanted when we installed.
4. You'll need 64-bit drivers for the server for sure since it's the server OS. If you have any clients installing or using packages or queues that are 32-bit (yes, we still have plenty here) then you need the 32-bit drivers as well.
5. I used and followed the Pharos migration directions and they were spot on and a huge help for planning the project. One of the easiest server migrations I've done.