Having to look at the left side(space), middle(arrow keys), and right(num0) of the keyboard, as well as the mouse, because I needed to click on things, is bad game design.
What would you suggest
Not requiring players to use the mouse, for one.
Also I kinda see you logic, situating everything at the bottom is a good start. I suggest you change from numpad 0 to one of Z, X, C, V keys.