Hi dekket,
Here’s the list of files and paths that Opera uses for their browser:
http://www.opera.com/docs/operafiles/ [Look at the Mac specific ones]
That should give you all the information you’d need to secure Opera. You might want to be careful and only encrypt folders specific to Opera and not system folders or files that are used by the OS X such as the:
~/Library/Preferences [This is a system folder]
There is also no need to encrypt your Opera.app package as it is not intended to be used to write your private user data information in there.
We’ll consider your request for having an app template for Opera. Thank you for suggesting it.