I'm not sure I have a coherent proposal. Clearly ISO-C is a cul-de-sac by now, and will have to be ditched. What we should replace it with is not clear to me.
It is a big problem that so many standards, requirements and tools (from EMACS to Coverity over lint) have their fingers in the C-syntax. The autocrap abomination is a further complication.
So I guess a good place to start is to swear that we will never touch or use the botched ISO-C thread API, and beat some sense into the WG14, by whatever means are available.