I've often wondered whether Palpatine's faith in his "friend," Darth Vader, led to his downfall. Surely, it played an essential role in getting Anakin into a position where he could defeat the dark lord, but there was also an arrogance which led to his downfall. I think Luke knew what he was doing when he verbally jarred with Palpatine when he was first brought aboard the Death Star. Luke knew about the pending attack of the rebels and he had faith in his friends to overcome the challenges they were going to face. He also understood that the Sith relied on overwhelming displays of power to compensate for their inability to adapt to different scenarios. For example, Maul could not adapt to the change in circumstances at Naboo. He had been fighting two Jedi and when one went down his focus shifted to the sole remaining Jedi. He forgot, however, to be mindful of Qui-Gon's sabre. Dooku failed to handle the addition of Yoda to his fight at Geonosis. Anakin could not handle the tactical changes that occurred on Mustafar. So too in the OT. The Imperials could handle a small group of rebel freedom fighters, but they could not adapt when the Ewok allies entered the fray. The Sith were simply incapable of adapting to change. That's why the Emperor had to believe that everything was within his purview and control. His attempt at foreseeing the future was inept because the future is always changing. His overconfidence in his ability to see the future was certainly a weakness which the Force utilized to bring about the balance it so desperately sought. I don't think the Force hurts our characters at all, except to bring about the balance the Force was seeking. The characters had to be in their proper place in order for the Force to achieve its ends. Luke had to face Vader on Bespin in order to learn the awful truth. The truth he learned only deepend his compassion for his father and thus enabled his redemption of his father whilst in orbit around Endor. Luke suffered and paid an awful price, i.e., he sacrificed his youthful naivete and his right hand, to get to the point where he would be the proper weapon in the hand of the living force. I feel like I am writing in circles at this point.