Maybe objects that go at speeds too high start falling apart like in the roche limit, but objects with very high gravity like stars would take higher to affect. Black holes wouldn't be affected on how high the velocity is.
A similar way goes with rotations too quick. The planet starts getting higher in oblate meaning it's wider, then it breaks, same goes with stars, but again, black holes are never affected.
That's my suggestion to make things a bit more realistic on rotation and velocity.