In C, I consider myself an 'old hand' (started with C86) and you state, yourself, that in C you are a newbie

I am not proposing anything definitive, irrevocable, half-intelligent nor anything which you don't use anyway - except the automatic flagging of variables as critical, which I propose to be optional and by default off
C, already is full of 'traps' many of them showing up by you 'believing' the compiler will tell you some thing that it is not supposed to, and thus rarely will. Such an 'option' would lead to many hours of debugging because the compiler - or you - forgot to flag one such case. Many "clerical errors" (e.g. '==' and '=') in C are caught by the compiler, but not on a constant basis and I almost would rather have no reports where the report is not infallible.

I believe a warning can't make any harm.
I can not count the number of cases whewre I have found someone elses bug buy removing his "warning suppression".

I believe automatic interrupt disable/enable (or any other mechanism) around manipulation of a variable flagged critical (manually, by the user) may be beneficial.
No, anything 'hidden' is very deterimental for two reasons:
1) you do not know it is there and thus, if it being there is a problem, you will spend ages hunting the problem.
2) you believe it is there and spend ages hunting the problem that, in this particular case, it is not.

Can you please avoid discussing politically and concentrate on technical issues?
I do not recall anything 'political' in this thread

Erik