While a virtual keyboard sounds like a good idea, I think it would be problematic. There wouldn’t be any tactile feedback and the positional accuracy would be critical.
I think a better solution would be to learn to touch-type (which would be useful in real life) or use VoiceAttack, so you can just dictate your text/commands. I use VoiceAttack in Elite Dangerous and it’s very useful. I learned to touch-type 15 years ago, using an internet typing tutor program. It was well worth the effort.
I can touch type myself, but you still need to know where the keyboard is first. Seeing it in vr makes it much easier
True. It’s usually on you desk. 
I can find mine in a darkened room. Most keyboards have bumps* on the index finger home keys (F and J). It’s not hard to position your fingers correctly. Of course, this assumes you are playing a seated game.
*My keyboard bumps are barely there any more. They have been worn away by years of use, but I can still find them and type in the dark. 
yes it’s really better