What game developers typically do for actions is using the either the ZXC buttons, in combination with the arrows for steering, or for instance the JKL buttons for people that prefer to use WASD to move around. Space for jumping is fine btw, I'm using my thumbs for that, which is not in an awkward position when using either ZXC or JKL.
I'm assuming you're doing the coding work on a desktop, so just try think from the perspective of a gamer and hold your hands on the keys. You will probably feel right away that certain key combos are a bit awkward :)