Fantastic questions, Rex, I can tell you are getting into it.

Still, when we are talking about a person as if impersonating a force, then the person embodies that force already by pulling a rope. Adding a mountain into the analogy is not a valid action, because the mountain does not pull a rope.

The collective force is far greater than any individual force, but if we were to add all individual forces up then we would in general still just get that one total collective force.

The trick is that there is an inherent system at play, and the word synergy must be mentioned then as well. Where no single star system in a galaxy can pull an external star system into that galaxy, the galaxy as a whole is capable of doing that. We see two levels of outcome therefore with one and the same force.

Next, all star systems pull on one another in a galaxy and yet much of this will end up in a balanced situation.

The spinning of a galaxy comes into play, because that outward pull has to be negated by an inward pull. As such, we know that there is a pull toward the center that we can call gravity. Yet to make it a single spot is not required. Earth and Solar System are pulled toward the center of the Milky Way by all stars in that direction. The heap of stars is found in that direction. So, we can declare that pull much the same as if the entire galaxy were pulling a distant Star System toward the galaxy; it is just that the circumstances change a bit once the Star System is inside the Milky Way.

You have a great question about the distance of a force. Allow me to answer it indirectly.

We cannot see forces, we can only see their effects.

With the Eye of the Storm, we do not see the wind. Rather, we see the clouds driven by the winds. Based on this, we can see that there is a net-zero position in the center of the Storm where there is no wind. We also see that the wind is strongest right next to the Eye. Yet we see it because of the effects of the winds, not the wind itself.

When looking at the image of a Black Hole/Eye, we do not see the force; we see the results of the force.

In model A, we declare that nothing can escape the center, not even light, and explain the visual that way.

In model B, we declare that the photons can't reach the center because the gravitational depression is at its max, not in the center, but a bit before the center.

For Model B:

The dark spot in the image is like the Eye of the Storm.

The ring of light is like the Wall of the Eye of the Storm.

The galaxy is planet Earth in this analogy, humor me.

The circumstances that established the Black Eye are like the size of the Storm.

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Lastly, the effect when pushing a lot of rubbish on a roadway with a broom. When we have a good push, the rubbish can actually land a bit further than the added force. It is called momentum, and it adds just a bit of fun to physics, don't you think? The rubbish gets just a tiny bit further than where it should have gone because the collective on-the-move created its own momentum.