Is it possible to have some minimum level of password protection for a TaskPaper document? Is this anything that could be implemented in the future?
I think this is unlikely to happen. I know some apps (such as Apple’s Pages, Keynote, and Numbers) do allow for password protecting files. But it would require a extra work to research and implement… and any bugs that I add mean what you thought was protected isn’t. I don’t think I’ll add this feature anytime soon.
Instead I would recommend:
Use the security of your OS X account to protect your files. As long as you keep your files in your account no one else should be able to access them.
If that’s not enough you can encrypt your files … here’s one approach to doing that: http://www.macworld.com/article/1053658/decmobilemac.html