Nice ideas!
a) I was originally going to add selection overflow but I forgot about it after trying to figure out how to do it with Unity's built in UI system. I just figured out how I can setup the navigation to do that so I'll be doing that after I finished typing this :)
b) There's not really too much to adjust with graphics other then weather effects, lighting is 100% baked and there aren't any other real-time effects being used other then the toggable post processing effects already implemented, there is going to be a draw distance option in the future though. A console is something I have tried out in the past that I need to re-implement, it's definitely something I want to have because debugging wise it can be useful and it also provides some fun commands to mess about with.
Menu modification is something I plan to semi-implement with the track and ship editors, I plan to have a system like WOPulse and HD so you can build your own mini-campaigns using custom content, it would be in a grid instead of hexagons though. HUD modifications is also something I had mentioned wanting to do quite a while ago, it's likely it'll be a feature much later in development though.
Then finally key configurations is something that will take a bit more work because I'll need to use a custom input manager,
Aybe had created one a while ago so I'm most likely going to implement that. Unity's default input manager doesn't allow rebinding at game runtime so I have no control over that right now. There is a config file containing settings though, check the userdata folder created in the game's directory when you launch the game.
c. That's a cool idea, I can't say it would be easily achievable through already existing tracks in the game because all the track textures are bundled into atlases so the environment is rendered in 1-2 sweeps as 1 object. In the track editor though it's something that can absolutely happen, I will probably end up making some form of basic modeling tools to go with the track editor at some point so that can be integrated into that.
And I use OBS Studio to record videos, I record then upload the output file straight to Youtube :)
Edit:
I now have a spreadsheet for all of the teams indepth stats, they're really unbalanced right now but I'll be working on that soon. Here's the link to it