I like your theory, it looks like you gave it some serious thought but, just a few questions. What would cause such a "finite bubble" if there are equal forces both at the center and outside the bubble? It seems very strange that if these forces can balance each other through the bubble, they shouldn't be able to balance themselves without the bubble. Also, my knowledge is limited on black holes so work with me; I was under the impression that black holes had specific mass that was very large but not infinite (otherwise we'd all be swallowed up), we just couldn't measure it because of the whole GR thing and the warping of space-time. This would also explain why black holes swallow each other sometimes. Lastly infinity is a very tricky concept because within it, one can basically say 1 = 2 and math goes all crazy. If this occurs, than all of physics as we know it goes wacky and the idea of balancing forces goes out the window, because just as infinity equals infinity, infinity doesn't equal infinity at the same time.