Its just the way the cosmos has developed. Gravity plays a large part too.
Yes and no because when you look up in the sky some of those stars are planets but techinacally they aren't stars.
Planets orbit stars, stars orbit a galaxy. Planets are not "on" anything. A lot of stars out there have planets - we are just finding out how many now that we have better techniques to find them. So probably all galaxies have at least some stars with planets.
No. The stars are too hot for molecules to form. That said, some of those stars have planets and some of those planets may have water.
Moons orbit planets. Planets orbit stars. Some stars orbit other stars, or orbit their mutual center of gravity. Stars orbit the center of the galaxy. Galaxies may orbit the center of the "galactic group".
Some planets seem brighter - not all of them. Planets are quite near to us, as compared to the stars.
well for starters, stars don't orbit planets. Planets orbit stars, but some stars don't have planets that orbit them.
No. Planets are objects made of some combination of rock, gas, and/or metal that orbit stars.
No, they cannot be both.
some do but that is it i am guessing
the stars and some of our planets
On the whole stars are much larger than planets, but there are some dwarf stars that are smaller than giant planets.
From Wikipedia, article binary star: "It is estimated that approximately 1/3 of the star systems in the Milky Way are binary or multiple, with the remaining 2/3 consisting of single stars."It should be emphasized that this is just an estimate - some double or multiple stars are hard to detect.