To answer the question about whether or not you should post multiple entries: it's best to keep your entry ideas to one thread! There will be many others putting in applications and it can get a bit messy trying to keep track of who posted what and what they are applying to be. The organizers have to sort through it all - and keeping track of how many applications one person has made is just another piece of info stashed onto their shoulders. Let's do them a favor to keep things easy! Ontop of this, I recommend you go in one idea at a time. Start with your favorite idea, the one you want to do the most, and see how that goes. Keep in mind that, just because you may not get an immediate response (or any response) during the process of applications being submitted, does not mean your idea was not accepted. All it means is that it's still in the running. You will know if/when your entry is accepted! Patience is the key!
So after you submit your application, and if you are told that there was a massive influx of gym leaders looking to play that type, just re-edit your initial post, change whatever needs to be changed - whether it be the whole app or not (that's if you want to! You may have the best idea of the bunch! ) and then post again within your [b0pv]same application thread[/b0pv] to let the organizers know that you had just made changes. You can edit your entry while the application period is open as many times as you'd like ([u0pv]but it's [b0pv]easier[/b0pv] on everyone if you make less changes than more![/u0pv] ), but once the entry period is closed and all applications are to be reviewed and choices made, you must be patient. An organizer will contact you if there are any questions, suggestions, or issues with your application that must be discussed.
Good luck!