All I can say is WOW!!! It looks amazing.
I stumbled across this thread while looking for inspiration for my own cockpit. Mine wont be nearly as detailed though. I think I might be able to solve two of your problems!
- Eliminate the need for a keyboard and
- Fill up the double DIN (stereo) hole.
My idea is to put a blanking plate across the stereo hole and fill it with 8 or 10 buttons/switches - one for each essential function (traction control, speed limiter, ESC key etc). Connect them all to
one of these, and you're good to go!!
I'm going to do the same thing in my cockpits (yes, I'm stupid enough to build two of the damn things). The little circuit board in the link above is basically just the brains of a keyboard, but with a whole lot of screw terminal inputs so it's really easy to work with. All you have to do is wire up your buttons and switches to it, and when you press them, the computer thinks you're pressing a button on a keyboard.
The only downside is that you don't have a full keyboard so you can't type messages in multiplayer.