The plugin looks nice and useful. Yeah, I would say go ahead and release it. Is there a way to control the visibility of the bars ingame? That way you could link them to an item, like in Chrono Trigger DS. You should also be able to choose which bar to display as most RPGs don't display a monster's MP, only the HP.

EDIT:
Also maybe you could also add the bars to the players? I know they already have their HP in the window at the bottom, but it would be more convenient to also display a bar next to them.