I think I don't understand... On one side, you say that C isn't that complicated but on the other side you say you just use a small subset because you don't trust yourself and your colleagues to understand all the C quirks...

I think C is complicated with all the 191 undefined behaviors and 52 unspecified behaviors (source for these number is the paper that the author of the quiz wrote for specifying CSmith). One must master C before having absolutely knowledge that the code that he wrote doesn't fall into one of the two black-holes (undefined and unspecified behaviors). For instance, almost everyone that I ask, they tell me that dereferencing a NULL pointer yields 'Segmentation fault' but it's just not true. It's in fact undefined behavior.

The other thing is the rules for strict aliasing... It's pretty much impossible to convert one pointer to another without breaking some of the C rules. The experts say type punning is the way to go but type punning relies in another not defined behavior. Reading an element from an union that wasn't the last element written is undefined behavior.