Rpg maker loads the entire map as you enter it, Runescape, however, only loads parts of the map. That's why when you're walking "Loading" pops up in the middle of the screen for a second. Scripts can't expand the editor itself, only the way the game runs. Though, it is possible to make a series of maps that appear to be the same map, using events. Zeriab wrote a tutorial on doing it. Hopefully he'll come to the rescue. .-.