I wonder how broken our astrophysical models will prove to be once we are more and more effectively able to peer outside our home system. There is a universe of examples out there, and I would find it slightly depressing if all of that complexity could be described by the theories of a swiss patent clerk.
Einstein's field equations are a system of extremely nonlinear partial differential equations. Actually using them to compute something is very nontrivial. And of course gravity is but one of the many forces at play here. You still have to account for thermodynamics, chemistry, nuclear physics, and other complicated effects to understand what's going on here.
