I don't get your last point. Fairphone doesn't have the hardware security measures that are needed to ensure gOS has its security needs. There are other OSs that are focused on de-googling like /e/OS (which you can have your Fairphone come with).
They shouldn't turn the project towards Fairphone as it defeats the project's purpose, if anything you could argue for them to maintain a separate fork but I believe when it was mentioned to them they pointed out that would split dev time and resources, reducing the security of the main project and that other OSs exist for those use cases.
Depends highly on luck and doctors. I hear it was near impossible from like 2020-2023, but its a lot more doable now