touchpad seems hyperactive and I can't figure out how to fix that either, but things change when I'm just trying to move the cursor around.
You only see the orange Firefox button if the menu bar is hidden: View > Toolbars > [ ] Menu Bar
Most likely you are showing the Menu Bar. Right click on a toolbar space and uncheck Menu Bar - the Firefox button should appear. You can toggle from one to the other.
Press [F11] - you're in a Full Screen Mode