I've been thinking about the episode, specifically the ending. And I think I've figured out a way to make the episode actually make sense, and have it tie in to the larger Ruby storyline in a really direct way.
Ruby is a reality warper. This doesn't come as much of a shock, she can make it spontaneously snow even on space stations or other planets. It may not actually be Ruby herself doing this, it may be a member of the Pantheon hitchhiking inside her and responding to her emotions (which always trigger the reality shifts), but functionally that part doesn't actually matter. Her emotions trigger observable shifts in reality.
What does matter is that the nature of the place, where the land meets the water, and possibly of the fairy circle itself and the implied supernatural factor thereof, somehow enables Ruby's powers to kick into overdrive and have a much larger and more immediate effect.
When the Doctor and Ruby first arrive on the cliffs, and the Doctor breaks the fairy circle, Ruby reads the wishes/notes. The very first one? "I miss you." Something you would say to someone you lost, as Ruby is about to lose the Doctor. In fact, he vanishes without a trace moments later. She also reads the Mad Jack note, which will play into Gwilliam later. At this point, The Woman appears. We know from the ending that this is in fact, and always has been, Ruby herself from her relative future.
What could future Ruby possibly be saying to these people that make them instantly turn on Ruby personally and drive her away? We are never told, but it DOESN'T ACTUALLY MATTER. She could be saying hello and asking them for tea. What's important is that after the Doctor disappears Ruby's fear of abandonment is driving her reality shifting abilities. It isn't actually what is being said to the people that is making them flee. That's just the outward mechanism manifested by Ruby's fear. This is how UNIT soldiers could be affected, how even Kate could suddenly be turned even just "hearing" the words over the comm unit. The words don't matter, all that matters is that Ruby fears being left, and so everyone leaves her.
A quick aside, but there is a bizarre bit of dialogue from Kate in her scene. She mentions that Ruby's timeline might be frozen relative to her event. It's never commented on, expanded upon, or even mentioned again. But there are two ways to interpret the line using this analysis, and both work delightfully, even together. On the one hand, this is a splinter timeline created by Ruby herself and operating basically as a tangent from the actual timeline. On the other, Ruby herself is frozen by "her event," her abandonment as a child. She can't move past it and it dominates her mind.
The Gwilliam stuff is such a weird anticlimax, but that actually makes sense now. It only happens because RUBY BELIEVES IT IS SUPPOSED TO HAPPEN. She creates the guy and he wins the election and becomes PM because she is basically willing it to happen, subconsciously. She then comes up with the clever use of The Woman to stop him and end his threat, which she does completely on her own without any help. She proves that she is smart enough, strong enough and capable enough to save the world without anyone else there to support her. And, coincidentally, she essentially embraces her true nature and true power for the first time.
This culminates in her approaching death decades later, when she has come to terms with being abandoned, but never alone. She then realizes that The Woman has been her all along. Which is reflective of kind of coming to grips with the fact that the only thing she needs to do is to accept herself, and that she is all she needs to move forward with her life regardless of how anyone else treats her. That even if everybody leaves her, she is still more than capable of living her life and being amazing.
And, with her fear of abandonment now more under control because of the revelations she has had on this journey, she is now able to shape a "different" path. It isn't really, it's the proper timeline simply jumping back on track after she derailed it for an episode. Which is why, at last, Ruby is able to hear The Woman in time to prevent the Doctor from breaking the fairy circle and kicking off the cycle all over again.
Edited to Add: Also, I would point out that they explicitly call out that at some point in Ruby's life, "it never snowed again." As in, she never made it start snowing with her emotional response again. Which comes after Ruby gives up on ever finding her birth mother. Thus, the emotional trigger for the reality shift stops happening.