It is possible to record in mono mode.
Notice the downward pointing triangle in the above picture to the left of "R M S". Click on this to get a pop-up and then make sure that Audio Record Input Select (InpSel) item is selected. Then from that column of the tracks window, you can select mono or stereo for the track to be recorded upon.
To record multiple tracks, simply shift-click the record column of the tracks window.