Wizzy, you get that ability after the rock concert mission in the lobby. Select Q/E for one click or square by square.

How do you toggle through the furniture selections?

how is everyone one click painting walls?

Fair enough

Instead of using the crowbar to destroy individual floor/wall sections, hold the left mouse button (heavy swing), and you'll see the area expand to bigger sections. Individual pieces take way too much time.

Work smarter, not harder.