I think that changing engines and adding more gameplay can be a good idea as long as the characterization and xplayer content won't suffer. Part of the reason why I kept up with this game despite the simplistic gameplay is because I genuinely loved interacting with the characters you've made.
There's also the issue of how long development will take in the pursuit of expanding the management aspect of the game, so perhaps updating the management bit by bit while also adding more events and interactions depending on the management goals met (or not) can be good?
I'm interested to see what direction you'll be taking this.