omg no. Stop obsessing about this dragon. I'm not sure I've ever met it in my life (you know, other than segfaults from NULL dereferences which are UB too).
I don't know. Quite a bit - maybe written 300K lines and deleted > 200K lines. Most of it was compiled by gcc -O2 and/or MSVC. I've never relied on vectorization or used a lot of intrinsics, though.