With 'System wide' I mean for example the searching for files but not going through the whole System: the drive on which the OS resides and possible other drives.
Give an example on how to limit a search.
Maybe there are other functionalities within listary that does things system wide, if so then provide example(s) on how to restrict them.
BUT as far as I have seen I think only the search does things system wide, so I think this could be a short one to implement. And I think If you provide use case examples for advanced users then you will probably cover this subject automatically?
I think (in my very humble opinion) if you do the following 2, you have 95% covered:
1. The listary options dialog window, cover each option displayed on the left side.
2. Give examples for (like you stated earlier):
* Casual users who only use the basic functions.
* Power users who want to customize it.
* Developers who want to contribute.
3. OPTIONAL: Mouse over feedback in the options window of listary
I think you don't have to do a huge manual, even a short one covering EACH option briefly and then examples (casual, power, developers) will unveil Listary's power.
Another tip would be to ask users on how they use listary (create a seperate topic for it that is always displayed somewhere at the top of the forum list and then notify users through). I think you will be very suprised on how users use Listrary to interact with their OS and can give you some pointers for your "examples" section for the manual.