I would consider point 1 a good thing, much better to use an existing, well tested library instead of rolling your own. Number 2 isn't necessarily a bad thing as long as you have control over the input. Also coroitines are just too useful not to use. Though win32 fibers wouldn't be my first choice
That is the only one that scares me on that list. Several of those other bits of functionality are occasionally seen in scripting systems that support in-place reloading and dynamic compilation of scripts.
What bit of functionality required setjmp/longjmp? Over the past few years I've only seen it used as an emergency abort when exceptions were disabled.
For the record: you're likely to use longjmp if you're using libpng, and use void* if you're using a C library that has callbacks (since user data is nearly always passed using void*). So in that sense those two don't seem really scary to me.
Though the lack of goto in that list worries me.
Don't pay much attention to "the hedgehog" in my nick, it's just because "Sik" was already taken =/ By the way, Sik is pronounced like seek, not like sick.
