Isn’t there supposedly a black hole at the center of the Milky Way and if so, did it or did it not figure in the formation of the galaxy? Or any spiral galaxy.
Yup. There is, in fact, a supermassivie black hole at the center of this and every other galaxy that is observable. It has been proven by measuring the speed of the orbit of stars near the center of each galaxy - the stars whip around something invisible at blinding speed and sometimes lose streams of material to the black hole. If you watch how fast the middle dot is spinning in the video, I believe they did use the black hole in their equations.
Fascinating stuff.