Proper procedure to activate Windows for use with both Parallels and Bootcamp?

Hi all,
I have Bootcamp on a MacBook, Windows is not yet activated.
I'm hoping to run the same Windows from either Parallels or Bootcamp.
My concern is how to properly navigate the Windows activation, such that I can painlessly use either Parallels or Bootcamp.
Just hoping for any clarification:
1) Purchase a "retail" Windows 10 key.
2) Activate Bootcamp with that key.
3) Boot into MacOS, install Parallels, connect to the Bootcamp partition
4) I think here I have to install "Parallels Tools" into the Bootcamp partition?
5) At some point, Windows within Parallels will complain about activation (because now it's running in the Parallels machine rather than Bootcamp) -- now I have to activate it a second time -- which, I gather, I can do with a retail copy of the key?
6) From now on, I can simply boot to either Parallels or Bootcamp, without any more activation complaints, is that correct?

One last question:
Are there any disadvantages to running Parallels with the Bootcamp partition? I read somewhere (though I can't remember where) that the Parallels Tools may somehow interfere with the Bootcamp tools when you've booted directly into Bootcamp.

It may be possible to have Windows installed separately into Parallels, and not use the Bootcamp partition -- but that seems like a a lot of wasted storage and double work (I'll still want Bootcamp).

Thanks for any pointers -- Windows activation seems like a potential pitfall, so I'm hoping to understand these concerns in advance.