There is a short delay after you switch cells, and sometimes typing too fast doesn't register. (which I'll fix in the next update) (Edit: fixed)
What do you mean by "you are forced to wait"? You should still be able to type during and after taking damage.
This game is a jam submission so it's a bit rushed. I'll update this with more convenient keybinds and address issues once the jam rating period ends. Thanks for the feedback. (Edit: updated)