Why so aggressive?
1. They have smooth walking like any other VR game, by holding a button and tilting the controller where you want to go.
2. Dunno, they're working on a patch apparently.
3. You don't, it works like any other game.
4. You aim your tool with your right hand obviously, but since you're in VR it's not tied to your viewpoint, so you can mine something while you're looking away. You use your viewpoint to target distant objects (and then press a button to set your compass there) or to target touch objects like farmable plants. When you have those lined up, you then hold a button and "pull" the thing to interact.
I think viewpoint aiming makes sense for distant objects, but there should be a crosshairs to make it more accurate. For farming, it could go either way but I'm getting used to it. It makes sense that you need to look at things you interact with.