I am a lefty but use the mouse with right hand.
IMHO, the minimap should stay in UR.
The mouse-move from main map to UR (and back) feels much more natural than to LR, as I seem to just pivot my elbow rather than strain my right hand/wrist muscles. This is likely my most common movement playing this game.
many of the 'list boxes' that currently appear under the minimap often extend down off the screen (unit placement, combat moves, combat on large maps). To me, it seems more intuitive for these to spill/scroll off the 'bottom' of the screen rather than 'into' another game area like the minimap.