The columns of the file view can be resized by clicking the mouse on the small divider between the column headers, and dragging the mouse to resize the two columns straddling the divider.
Shift clicking extends the current selection, and control clicking toggles the selection.
Right clicking (windows) on a file or directory icon will present a context sensitive popup menu that will allow you to run commands directly, instead of having to select the file and then select the command from the Selection menu.