Is there a way to print entire SMS conversations? Even individual messages would be a help. I have backed up the database with the desktop software so I should have all of them, I just have no idea how to get them out in a printable format that could be used in legal action. Can anyone help?

If you use desktop manager to back up your BB on a PC, it saves the file as an "IPD". You can use this software to open that backup file on a PC and read it.
It's $20, but it has a free trial, I believe 30 days. I haven't used it myself, but I've seen it suggested a few times.

Hope this helps.