If you have read the threads so far, you already know that the only thing decided so far is to start a project.
Since the exact scope of the project is not even formally decided yet, saying things like "what exactly are you going to do" is premature and frankly not very helpful, the goal is to produce a distibution suitable for in car use out of the box, beyond that nothing.
Planning an operating system, or more precisely correctly customizing one, requires having precise goals in terms of functionality, stability and deployment consistency. Putting the cart before the horse would not achieve anything. Your suggestions would be further down my list if I were implementing this, defining and achieving the exact requirements for the frontends in terms of software dependencies and hardware support would be a whole lot more important, tuning and tweaking prematurely breaks OSes and costs more time than it saves, but even that is premature.
At this point I would be looking more at things like the following from the OS:
From a design perspective ( OS and frontend ):
1. Dependencies of the front ends.
2. Tools required for development only
3. Supported hardware
4. Required services
An implementation perspective ( for the OS ):
1. Baseline Bootstrap environment ( the reference system for the first build )
2. Code repository
3. Code handling rules ( branches freezing etc )
4. Build systems, ideally every build should require only one command to run, be reproducible, and report it's exact baseline.
Only when the above is achieved would I consider adding or removing anything in terms of functionality or features.
What you term
PR I would term "cultivating interest", there are currently only two people on this project how else would they be expected to attract help and input? In this case the "
PR" is required to get the input to define the actual goals.
EDIT: I am not a member of this project, merely an interested observer. I merely know what is involved in providing a customised OS, and do not wish to see the guys who are taking the task on fall into the trap of trying to please the stone throwers.