need help for possible future supplements

[Green]

Now that my Kathanaksaya website is complete, and I have managed to playtest it a few times with some on-the-fly games, I believe I would like to continue developing this game.  It would be great to create supplements for different genres and settings.  Due to the nature of Kathanaksaya's design, I realize most of any supplements I have would be flavor text as opposed to rules.  However, I am unsure of where to begin.  

One of the goals of these supplements is to introduce/develop specific genres, settings, and themes for games as well as to give players the tools necessary for creating these things themselves.  Yet, I wonder: Which approach should I take, and what are the advantages and disadvantages of each approach?  Should I go in from the genre angle and craft a setting and themes with genre expectations as the foundation?  Should I go in from the setting angle and reveal genre and theme?  Or, what if I center supplements around a theme and use genre and setting to elaborate that?  Basically, I guess I want to know if I should use a deductive or inductive approach to supplements and to determine possible pitfalls and potential gold mines of each strategy?

Right now, I am inspired by my recent purchase of the "Best of Bowie" DVD and my current reading of Greg Bear's "Songs of Earth and Power."  Right now I know I want a gothic fantasy setting, but I am not really sure if I want to emphasize the genre, the setting, or the theme.  As it stands, it seems that the genre is what I would focus on, but I don't know if that is the best approach for supplements.

How would I go about doing this?  Do I take a cue from Decipher Games and create the setting and make a blurb about the genre?  Or do I create the genre and make the setting as an example of the genre?

As far as mechanics goes, although there would be few of them, I was wondering about allowing settings to be characters as well.  There are plenty of examples of this in literature, so it wouldn't be too remiss.  

What sorts of things would you, as a potential player of Kathanaksaya, want from a supplement?

[Lxndr]

Not that this means much, but you should design things however seem best to you.

As a consumer/client/customer/player/GM/whatever, I'm most interested in rules tips, setting concepts, etc.  Give me a nifty-neato setting, and reveal the assumptions underneath.  Show the sorts of attributes, skills, backgrounds, hooks etc., that you expect the setting in question to have, and not to have.  Sample characters, sample locations, maybe even a few story seeds...

As a designer, I'd stab at the setting and let genre and theme grow out of it, rather than vice versa.  But I'm not (yet) a successful designer, so take that with a grain of salt.