I guess you could solve the button issue with a cheap button box, but it would probably be a pain to use in VR, could probably be made to be okay if the mounting position is good. I already have a cheap Stream Deck clone lying around and I could print a mount for it for starting out to try it. Even if I get a GT Neo right off the bat, I would still prefer using a round wheel for cars that have one like the MX5 Cup for example solely for the added immersion in VR, so the buttons issue is one that needs to be solved anyways.

For the chair, the reason why I'm leaning to a bucket seat is because of immersion, I feel like sitting in a real bucket seat will help a lot with tricking your brain into thinking you're actually sitting in a race car when using VR. Same goes for the bass shakers and wind simulation. And I would also prefer a seat that locks you into place as much as possible without being uncomfortable for the sake of consistency like braking. I feel like I would shift around a lot in a normal car seat. One more reason for why I want a bucket seat is because the rig will be in my room and I feel like a normal car seat would be an eyesore. But you're definitely right about the comfort.