First of all this seems like a great application and idea, but I believe that users should be instructed to BACKUP data until they feel comfortable with its stability since I have noticed several bugs of data corruption...
Second of all
I see you use "burp" for blowfish encryption which is very nice but have you seen http://bcrypt.sourceforge.net/ ? I believe this application users a more secure implementation of the blowfish algorithm if you want check it out and verify for me. maybe in later releases you can use this as a backup for the blowfish algorithm
(there is also http://ccrypt.sourceforge.net/ for another AES backend, but I haven't used it, just posting as a FYI)