T2D uses TAML as its persistence system. You can save any object to file using TAML. Simon shows an example of this here and here. Essentially, you use a ScriptObject to store the data. You then call TamlWrite to save it to file. It defaults to saving in XML format, but you can also choose JSON or binary. A couple of other T2D users have been working on implementations that will add database support, so that will soon be another alternative.
Happy to help. If you want some protection for the end result, use binary. It's not human readable, which makes it less possible for your average user to edit.
Employee Michael Perry
ZombieShortbus