Isn't windows "Installing new hardware" every time you boot? And the license is still active? I was always affraid it will break the system after few switches between virtual and bare-metal boot.
It does like to deactivate itself after a few reboots, but that's nothing a bit of mild piracy can't fix. I have at least two spare windows licenses in a drawer so I don't feel the least bit bad about it.
I also have a big ugly powershell script that runs during startup and does some things differently depending on where it's running. Things like not launching all my background stuff in the VM, remapping drive letters between physical disks and VM folder shares...
Another thing to look into is RemoteApp. I did some experiments with it in a VM and the performance was way better than "seamless mode" (which doesn't exist anymore anyways), but getting it to work on non-Server editions is a pain.
(Windows did just crash when I was testing it but, as it also crashed twice before I got that far, I don't think it's related)