Is 同級生 ever used to simply indicate that two school-aged people are the same age or of equal status to each other, regardless of where they go to school?
The person being referred to with this lives in another town from the person he's supposedly a classmate of, so I don't see how they can actually be in the same school, let alone the same class.
By the same token, is 先輩 ever used for someone who is simply older than you and ahead of you in school, even if they're not in
your school?