There is no need for graduation or degree certificates. And there is also no need for the seal over the envelope. I just checked with LSDA JD CAS. And all T14 schools except Columbia and Yale, require using the JD CAS service. That also includes Georgetown and UCLA. Hope this info helps.
It is NEEDED. You will need to send in your transcript together with degree and graduation certificates. It has been confirmed with the LSAC JD CAS and with AACRAO who will actually evaluate the transcripts. Then I guess from the safe side, it is better to ask the school place a seal over the envelope as well. Sorry for the misinfo that I gave in the previous post.