I had problems with both those quests too, actually with a lot of the personal quests. I was finally able to complete the circus quests, but haven’t been able to complete Set to Blow. I was able to clear out most of the regular destroyers, but by the time I did all my equipment had broke and I couldn’t get the boss no matter what I did. I was doing Set to Blow with 50th level thief. I have found I have a much harder time with the personal story quests with the thief than I have had with the other classes I have tried.