The right mouse button is for selecting.  Hotkey 'c' is for circle select and once in circle select the left mouse button does the selecting and the middle scrollwheel button unselects.  Hotkey 'b' is box select, hold and drag with left mouse button then release to select, hold and drag with middle scrollwheel button then release to unselect.  The right mouse button is for single select, hold the shift key to add selections one click at a time.  To move vert(s) the hotkey is 'g' for grab.  The vert(s) will move with the mouse until you click the left mouse button.  While right click and hold will cause the vert to move I see this as more of a non fatal bug that the developers don't see the need to waste time to fix.