The Companions quest-giver/follower Aela the Huntress has given me two major quest bugs. One of them is a potential game-stopper.

Right before I had the chance to take the "Glory for the Dead" quest, I asked Aela if she had any work for me. (I didn't realize the "Glory" quest was about to trigger.) She gave the quest "Retrieval." That was a problem, because I had already completed the necessary requirements of that quest in an early quest, so it was no longer valid. But the quest could not be finished or cleared from the journal, preventing me from getting any further "looking for work" quests from the companions. (Clicking that dialog option just gets a response to the effect that they already gave me a job to do.) Console commands to finish "Retrieval" did not work, and neither did attempting to perform the quest in-game.

A second and worse part of this glitch: After several more hours of gameplay, I suddenly got a map compass prompt (but no journal quest) to go the Companions and get a quest from Aela. That turned out to be "Totems of Hircine." So I thought I was somehow getting around the first glitch. Aela had a new dialog option offering me the quest. I accepted the quest and she became my new follower, booting the one I had. But then she did not follow me. However, I was treated as though she was following me; if I attempted to get any other follower, they told me that I already had a follower, even though I literally did not. My only dialog option with Aela after that was to ask her for work, and she replied only that she has already given me a job. I could not dismiss her and could not pick up a new follower. A console command to finish the quest worked.