[@MrSkimobile] Well, for the map, that's to help visualize the setting, and of course, figure out who is who. Just draw up yourself a claim, set a sheet with your nation's lore and you're set! 

As for Nation RPs, they come in a variety of flavors. My brand, as well as others, is more narrative/character focused. We don't "play" as nations per se, rather we play as the people within. It's more of a large-scale version of your typical RP where we can play as a large cast of characters in addition to other player's casts of characters to drive a particular story or several.