Can you enhance the multiplayer dial with the Trench Run card (0150)? If so, does it require more to destroy the dial? Also, When playing the Jerjerod's Task challenge deck, can you destroy the dial to make it easier for a light side victory?

You can enhance the multiplayer dial with the Trench Run card, but multiplayer rules specify that you cannot change your own side's win condition. So you can stack as much damage on the dial as you want, it won't let you win the game.