Syscoin is a great project.    I am an experienced C++ developer and I am impressed with your code in Github that supports Aliases, Certificates, Escrows and the Blockchain market. 

I don't think the encrypted messages should be stored on the blockchain.  Yes, it is encrypted with a 256-bit ECC key but, IMO, all encryption will be broken one day and replaced with something better so it is not a good idea to leave encrypted data in a public place like a distributed blockchain.  Something like MaidSafe's Safe network where the cypher text is cut into many pieces and distributed offers much more protection.