It's a theory in the weakest sense of the word. We really have no idea what happens to black holes when they get that small

Because the government actively encourages oligopolies

1. We don't know. All observations and theories are consistent with either option

2. The law of conservation of mass (which doesn't even hold anyways) has nothing to do with this. There's no mass or energy associated with just space itself. And it's not being created so it doesn't matter

3. Space being finite doesn't mean that if you were to travel forever you would eventually reach the edge. The surface of the earth is finite but there's no edge

All sperms don't carry the same DNA. The father has two different versions of each chromosome, and each sperm cell randomly gets one of the two versions of each. Same with the egg. Each sperm+cell combination therefore gets a combination of chromosomes that is different from other sperm+cell combinations

You already do. Anything with mass (actually, anything with a stress-energy, which doesn't even require mass) bends spacetime and creates a gravitational field. If you were as heavy and dense as a black hole, well, you'd be a black hole

If it has an event horizon it's by definition a black hole. That's what defines a black hole, not the singularity. According to general relativity any black hole inevitably forms a singularity (under some pretty safe assumptions) so any object that forms an event horizon will also result in a singularity. But we believe that general relativity isn't accurate near the center of a black hole and needs to be replaced by a theory of quantum gravity, and that this will get rid of the singularity