I didnt really have any thing as far as the roster just that the oldest is going to be 20 and male but that was only because thats how i wanted to have my character other than that id say no younger than like 10-12. As for the Gundams I wanted to have them be unique so as far as the customization goes run wild just dont make them super over powered. Like I'm talkin Absorb system to power a trans-am system levels of Over Powered.