This isn't the first song that Rush wrote that addresses the struggle of youth.
Proud swagger out of the school yard
Waiting for the world's applause
Most notably in Subdivisions. I would say that War Paint, also on Presto, reflects the mindset of youth as well. Then there is Kid Gloves which is a bit of a lesson in growing up.
I think Neil really understands what it's like to be a kid. I would guess that his time in school was somewhat difficult. He was probably a lot like that kid from the Subdivisions video. Probably bullied (smart/nerdy kids always are). I think those experiences might have shaped his personality for years to come.
The Pass is quite obviously about suicide. It begins by being very empathetic. It makes a best attempt to convince the person that they don't have to go through with it, that there is another way, that they don't have to go it alone. But the song finishes with... the person jumps anyway!
I would say that Neil is, for the most part, very positive with the messages in his lyrics. While he can be very critical of society in general, when it comes to another human being, he is, as I would say, closer to the heart. So I think The Pass is a rare exception where his imagination allowed him to go a bit into the dark side of humanity.
I pondered for a long time about how this song fits into a central theme for Presto. I first thought Presto was a nod to magic, but that doesn't fit. I then thought it was about the wonders of life, sort of a nod to the miraculous process. I now thing that is wrong too. After reading the lyrics to The Pass again, I think the answer is a bit sarcastic.
Presto, is about how things get by...without magic. It's about reality of life. Reality of emotions. Reality of the biological process. The reality of the dark side of humanity. Neil is saying that there is no magic here. It's not miraculous. What people see as a miracle is really about the small and difficult steps people take. The miracle of a person not committing suicide is to for them to turn around and turn around and turn around, turn around and walk the razor's edge. Meaning that every day a person has to struggle with their depression and every day, if they don't jump, it's because they were persistent in their turning.
I think this was finally confirmed 4 years later in Everyday Glory. Which perhaps would have been a more fitting closing song for Presto than Available Light.