For a personal painting like this, I'll flatten the image often, with the layer count reaching no higher than say, 20. For client work however, I'll keep any important layers separated and grouped so certain elements are easy to edit making the layer count much higher.
It's so brilliant to see an artist at work like this at photoshop. I'm still trying to figure out how to make digital art like this. Where did you learn? From school? Somebody telling you? Or on your own, cuz if it was on your own hi-five and a bow to you good sir!