Editing positions on the map
The map understands a few mouse gestures directly, without opening a menu.
Selecting positions
A left click selects the closest position within about 15 pixels, replacing whatever was selected before. Shift+click extends the current selection instead of replacing it, so you can pick several positions one after another.
Inserting and removing positions
Ctrl+click inserts a brand-new position at that point on the map. Ctrl+Alt+click deletes the closest existing position — there's no confirmation dialog, so undo (Edit → Undo) is the way back if you click the wrong point.
Moving a position
Drag its marker to a new spot. The position list and any elevation or distance figures update as you drop it.
Zooming
Zoom in and out with the mouse wheel, or the + and − keys, centered on the mouse pointer or the current selection.