Moving Parallels 11 to a new computer

I am updating my computer: 2012 Mac Air with 4G memory isn't enough to run P11 and Win10. But I have several questions and I've been through help pages that seem to suggest different solutions. I also don't want to clone my drive--I'm going from a 256 Air to 512 MacPro is 16 gigs, so the drive sizes won't match. Apple suggests they can migrate, but I want a clean install. Several questions:
1. My Win 10, upgraded over Win 7, seems to be Win 10 but everything in Parallels menus still say Win 7. What's that about?
2. If I get a clean El Capitan, can I use Apple's migration assistant to move that partition?
3. I have back-ups, and I see Parallels 11 says it backs up the Win 10 partition, but I'm not very trustful of that since it's an upgrade over Win 7. Can I get a fresh Win 10 still off the Parallels site?
4. I think I have to uninstall Parallels from the old drive, if I read some of the tips right, but my download of Parallels 11 expired last month and I'm not clear where to get the software to put on the new computer.
5. What other slip-ups do I need to avoid? I have not found a clear step by step on the web--I admit to being a capable old Windows user but I'm relatively new to Macs and I'm often baffled trying to find stuff in Win 10.

Any help, thanks. When I actually get the new computer next week, I just might have to pay for support....

 

Hello @Gillie ,
Here are a few useful tips for you
1. You may change the Virtual Machine to Windows 10 as outlined in this article
2. It is always recommended to make a manual backup of Windows 10. Here is how you can make a manual backup.
3. Here is a brief guide on how to download Parallels Desktop 11 for Mac and move it to a new Mac.