Misleading title: the watermark applies to AI generated/edited images. That includes local models.

Whether it applies to non-AI generated images is a question for the reverse engineers (or ironically, a suitable AI). My bet is on "no".

Of course, the pre-AI versions of paint and notepad can still be installed with a bit of trickery, and it's worth it just for the UX.

Don’t care.

There is no reason to assign a GGUID except to identify the person, not that the photo is generated. This is nothing more than surveillance.