The question that I started off with was, I thought, very simple. It was just 'Is there a massive black hole at the center of the Milky Way?' But one of the things I love about science is that you always end up with new questions.
The star S0-2 orbits around Sgr A* every 16 years and will go through its closest approach in 2018. That's an opportunity to test Einstein's General Relativity theory through very precise measurements of this star's short period orbit.
Gravity wins over all other known forces.
Our galaxy's pretty ordinary, garden-variety. So if we believe our galaxy has a super massive black hole, that tells us that most, if not all, galaxies host such a black hole at their centers.
Fortunately, most things around the supermassive black hole are just going to go around it. They're going to orbit it. They don't actually get sucked in.