I agree with the map no really needing it, could be just a fun thing to try out. That's why I mentioned just making it minor and exaggerating it a bit with FOV. Just an idea I got because of the minor diagonal speed bug, since it was fun speeding around a bit.
It's great to hear that you have ideas already for the other things I mentioned, I hope you end up implementing them. Either way, it's good to think about these kind of things since it's good experience for future games, which I hope you keep making :)