As far as the DRM'd stuff, yes, I think the registration is a difficulty. The new device might need to be registered under the same account, or the orignal user/password information has to be put on the new device (however it's managed).

As far as everything else is concerned -- user-created Journals, unprotected PDF files, etc. it appears everything is unencrypted and just connected together with a series of sqllite database files. It shouldn't require (much) rocket science to get a journal created on one edge added to the library on a different edge.