I think you are missing the point of the engine. Mode7, 3D mazes, and FPS games are not what it is being made for. It is not supposed to be THE BEST ENGINE OF ALL TIME. It is, however, supposed to be powerful and efficient for creating 2D games. The first version I think will focus solely on RPGs, perhaps later versions may provide framework for other types of 2D games such as platformers, shooters, etc.
Anyways, I'm definitely looking forward to the engine so that it can develop the RMXP community into a slightly more skilled and sophisticated game dev community. RMXP puts limits on the growth and natural understanding of how a game works, but your engine removes or raises a lot of those limits while still supporting low level introductory interaction, which is a very good thing