Hi man,
Not fully sure about what you asked
You can parent your char to the world, and sure the camera to the char ,
So if you rotate the world, from the player and camera nothing change but the sun.
I dont get if you want to be able to fall ( so the player dont have a gravity that push him to the cernter of world, and so is unable to walk all around it)
or if you want to be able to walk all around it (the player need a behaviour to walk on all the surface, upsidedown too, and so is unable to fall off)
or if you just want to stay balanced upon the rotating world, like a actobat on a bal,