Our universe is expanding constantly so there is nothing anywhere that is stopped.
A black hole
By under control, I assume you mean keeping it from drifting around, accreting everything in its path. The only way to do this (And is naturally done) is to keep it orbitting its parent star/galaxy. Stars naturally continue orbitting their parent after collapsing into a black hole.
quasar
Usually at the center of a galaxy or where a large star has exploded.
Most stars orbit around the center of a galaxy. Some stars are parts of star clusters; in that case, they will also orbit around the center of the star cluster.
The sun is a star and the only one in the solar system. It does not orbit any star but rather orbits the center of the galaxy.
The direct center of the galaxy varies constantly based on the movement of planets, stars, and celestial objects. The center of most galaxies is based on a large star or planet but may simply be an open space.
There is no singular star in the center of the universe. Our universe is vast and does not have a center. Stars are spread throughout the universe in galaxies, and our sun is just one of the billions of stars in the Milky Way galaxy.
Yes, the Sun is a fixed star in the sense that it is a stable, self-luminous celestial body located at the center of our solar system. It is one of countless stars that make up the Milky Way galaxy and does not move in relation to other stars in our galaxy over short timescales.
They do not; the Earth is well away from the center, in one of the spiral arms of the galaxy.
yes. every star is a sun. each star could possibly have its ownplanets orbitting it(like earth).
No. The sun orbits the center of the galaxy, not any star. Alpha Centauri just happens to be the nearest star system to our own.