This is a gross net effect, caused by universal expansion, our Local Group of Galaxies are 'gravitationally bound', which is to say the force between them from gravity overrides expansion. Expansion is roughly linear, double distance, double expansion rate, whereas gravity is inverse square, double distance, reduce force by a quarter. Hence inside a galaxy the expansion is effectively irrelevant. And unlike Stars or planets, galaxies aren't relative tiny dots on an empty ocean, but more like houses in a semi-rural area. We actually define the local group as those galaxies and satellites which will remain together (and eventually merge into one blob) till all creation sputters out.



No, again gravity is weak but not that weak. Hubble's Constant is at light year range amounts to about 20 mm/s per light year, or for context, 1 meter per 50 seconds, or 600 km a year, or 1 light year every 15 billion years or so. All the various stars flit around the galaxy under local accelerations and velocities relative to miles per second, not millimeters, at local galactic scale it's like a mule pulling against a team of horses, but inner-galactic it's like a cat pulling against a train. At the Galactic Supercluster scale, between those, the analogy reverses. Hence the universe is falling apart but it's individual sections remain coherent and would merge, minus some bits ejected by the merger.



Probably, many have, I generally warn people of developing personal theories about it.