I think your battlers are cute... and incorporating new materials into RPG maker is very easy. The only thing that takes a little advanced knowledge is the raw mechanics of the engine itself... but in truth, between eventing and scripting, anything is possible. By 'raw mechanics' I am specifically speaking of the menu, the battle system, and the ability to save/load games. Again, all is ultimately customizable (especially if you are good with scripting).
Graphics and sound in particular are crazy easy to import/customize. After I finish my current project, the next project will consist entirely of custom graphic (and if I have the time, custom sounds).