1. Jack convincing Sun that the loss of her ability to speak English is due to aphasia, and that it's "all going to be alright." He knows this is not true. And he was acting EXACTLY like FLocke in trying the gain the trust of "his" people. We now know for sure that the Evil/Good sides are not so, um, Black and White.
2. Widmore's assertion to Jin that if MiB gets off the Island, the people that they love (innocents like Ji-Yeon and Penny) will "cease" to exist. Widmore never said that they would be killed , or that the World would be destoyed. By using those words, perhaps he was revealing that sinners like Charles Widmore and Jin may be judged by MiB and eliminated in another timeline, therby making it impossible for their children to be born?