Fine tuning argument assessed

[LostLocke]

So the black hole theory states that the black hole will suck up anything that gets into its critical gravitational field. That makes the black hole even more powerful. So it keeps growing and its critical gravitational area gets larger and larger. So at some point the black hole will consume everything in its galaxy.

Nope.
There are dormant black holes around. They "ate" everything within their field. No matter how strong they get, they can run out of stuff to "eat".
Plus, no matter how close something gets, as long as it doesn't drop past the event horizon (which can happen do to the enormous amount of energy something has while orbiting close to a black hole), it won't get "eaten".