I'm kind of with you on the coding-style warning flags. it does really bother me that some opinionated person has decided that the way I use parenthesis needs to be punished.

but I totally disagree with your second point. running code often has real problems with race conditions, error handling, unwanted memory reuse, out of bounds pointers, etc. if a new version of the compiler can prove these things for me - that's invaluable.

I too love those features. Just behind an option, so that existing scripts etc still continue to work.

If many of those features are being added and the flags might add up to become a pain, then even a group flag -f-new-safety-features or whatever.