I found it a real pain to work with CE I've to say. I too sought for a solution to at least get the schema of my db in sqlserver CE, and after a long struggle I managed to export a DDL script onto the PDA, import it the QA lookalike tool on the pda for SqlCE and after modifications of a lot of things I was able to create a db.
There should be some tools for sqlce replication with sqlserver, though I'm no expert on that. As drewes said, llblgen pro can't help you there, other than working with xml data from/to a server/webservice.