Yes. You can make a low-resolution monitor (like 800x600px, once upon a time a usable resolution) and/or provide zoom and panning controls

I've tried that combination in an earlier iteration of Lenovo's smart glasses, and it technically works. But the experience you get is not fun or productive. If you need to do it (say to work on confidential documents in public) you can do it, but it's not something you'd do in a normal setup

Yes but that can create major motion sickness issues - motion that does not correspond top the user's actual physical movements create a dissonance that is expressed as motion sickness for a large portion of the population.

This is the main reason many VR games don't let you just walk around and opt for teleportation-based movement systems - your avatar moving while your body doesn't can be quite physically uncomfortable.

There are ways of minimizing this - for example some VR games give you "tunnel vision" by blacking out peripheral vision while the movement is happening. But overall there's a lot of ergo considerations here and no perfect solution. The equivalent for a virtual desktop might be to limit the size of the window while the user is zooming/panning.

For a small taste of what using that might be like turn on screen magnification on your existing computers. It's technically usable but not particularly productive or pleasant to use if you don't /have/ to use it.