This sounds really incredible, not only does it add a sense of time to the game, it's also a really good way to increase stats and xp outside of just battling. I really liked this concept in persona 3 and 4 and am glad to see it being used in an RM game.
The only thing I can really see that might be an interesting addition that would fit in what you have listed here; is a friendship or relationship meter. I don't mean like in persona that unlocks story plot and a new persona. My thoughts is maybe have characters work better together in combat when they have higher friendship, maybe even unlock new attacks when those members are in the same team.
I'm not sure if this fits into your game or is even something you'd be able to do, but I think it'd be a great addition. Aside from that it looks really really interesting and I can't wait to see it implemented.