Would it be possible to create two versions of the language: microC for embedded C programs where these decisions matter, and standard C for PC/servers which basically all use the same representation for these scalers?

My main point is that a C programmer today is forced to learn dozens of rules just to cater for many niche platforms that they will probably never target, so if you were to separate those two use cases you can get a much more neat C that targets modern 64 bit architectures with all the power of traditional C but a bit less portability.