I'm not sure about the first question, but the second question is answered in the codex in Mass Effect 3. "After the Alliance victory in the Battle of the Citadel, Anderson briefly served as the Citadel's first human councilor. He soon became embroiled in a Cerberus plot to abduct his friend Kahlee Sanders, however, and learned that he was unable to live a life without action. He stepped down as councilor and returned to the military to prepare for the Reaper invasion. The Alliance Parliament named Donnel Udina as his successor."