2. No, if the distance to the target is 10 hexes or less in a straight line, the penalty does not apply. Regardless of obstacles.
Added 2 minutes later
I understand that MP depends only on the speeds of the monsters (if there are no additional conditions). So, for Valeska, she will always have archers (or maybe a pikeman?) plus she specializes in archers, therefore, she will have a constant MP of 1630.
The same applies to Shakti.
Or am I mistaken somewhere?