Skill Hot Swapper.

Pressing Open/Close key (K by default) will open a skill menu select. First skill images indicate skill family. After selecting skill family there's another set of skill images to pick from that indicate the skills themselves. Clicking on one will change current base skill to the picked one. If picked skill is different than previous, cooldown and stocks will reset.

Future updates

Make controller support.

Prevent selecting locked skills. Personally I don't care