1 can never happen, at least if you’re defining “normal” as currently fashionable sunglasses. AR maybe, but VR needs full color displays at a certain distance so the eye can focus and it needs to block out other light sources. And then the power source and computer needs to connect somehow. Maybe, as in sci-fi maybe, we can develop a superdense high-definition display that beams directly into the retina while compensating for the lens, variable focus, and general motion of the eye so it can sit an inch away and look crisp, but I can’t imagine that being realistic this side of fifty years (and it doesn’t solve the energy or processing problems). VR is either not going to be mainstream in our lifetime or everyone is going to accept wearing a shoebox on their face for the experience.
2 and 3 are reasonable requests, there should be headsets that are as attainable and compatible as a standard monitor.
1 can never happen, at least if you’re defining “normal” as currently fashionable sunglasses.
https://www.evenrealities.com/en/g1
Add an electrochromic layer for VR.
You can already get cheap enclosures that you can put your phone into to make it work as a VR headset.