My two-cents: stay away from RPGM as a game engine unless you really, really want the top-down jap rpg style experience. While it is relatively simple to do some basic map / battles style game development, it becomes very complex and frustrating as you try to add more interaction (vn style dialogues, cutscenes, images) that is outside the built-in rpgm model.
Again, with the exception of building a basic top-down rpg with the pure jrpg game elements, it is at least as time consuming to create something in rpgm as you would find in any other engine, and the crutch of editor program is not actually that useful in the end.