I completely agree that highlighting code with regexps is almost useless, but if emacs is not capable of doing more than that (or its language modes usually do

I completely agree that highlighting code with regexps is almost useless, but if emacs is not capable of doing more than that (or its language modes usually do not do more than that), I think that emacs is at fault here, not syntax highlighting. In sublime text, for example, the syntax definitions are basically stack machines (if I'm not mistaken), and can therefore parse any context-free grammar. This is clearly powerful enough to handle all the edge cases you mention.