How do astronauts combat nausea in space? Practice. I personally don't expect a technical solution to this any time soon. We just have to acclimatize ourselves.
The target audience for VR is everyone.
A lot of discomfort for relatively little (at least thus far) gain.
Aww. But I already had my scalpels out for DIY inner ear surgery. I just finished watching the YouTube howto and everything... :(