User blog comment:EmpyreanSmoke/Supernatural Q&A/@comment-79.115.70.55-20150827160328/@comment-24834479-20150830062956

1. Their rings were forcibly removed, so not only did they lose their powers, but they were severely weakened. If they got their rings put back on, they could heal and become active again.

2. I think that Michael and Lucifer would be fighting with each other and also torturing Adam. The seals were meant to be a one time deal. So I don't think the cage can be opened through seals if there is no final deal to break.