Both the Parallels and Fusion sites have explanations about licencing issues when using a Boot Camp installed Windows as the guest operating system. It is not difficult to register again and it is necessary since when running Windows in a VM causes Windows to "see" new virtual hardware. So Windows "thinks" it has been re-installed on a new computer.
This is just the way it works and it is a simple matter and only required once to re-register. No big deal.
By the way, Fusion does not "take over BootCamp". Both Parallels nd Fusion can use Boot Camp installed Windows. You do not need to re-install Windows to use it in Parallels or Fusion if you already have Windows installed using Boot Camp Assistant.
"Some of the reasons:
- I really don't want to futz around with Windows' tools.
- I try not to go online using Windows. Especially since changing ISPs & losing the Firewall on that side!
- It didn't work when I TRIED to go online. I don't really want to debug Windows. That's why I run a Mac."
1. Then stop using Windows. If you didn't want to "futz around" with OSx tools you would just stop using OSx. Every OS has tools needing to be used at some point or another.
2. That is just paranoia or poor understanding of safety and using the Internet. Millions of users go online with Windows.
3. You don't have to "debug" Windows. If it did not work then you have not set up your connection correctly or do not understand how to go online. Windows "goes online" very well and it is rare that there is an issue not caused by erroneous configuration.
"I've read a little online that seems to point to Fusion being the issue."
Then go to the Fusion site and read their help and support pages. Fusion clearly explains on their site, As does Parallels, how to deal with using Bootcamp installed Windows.