I see a problem with body repair questions as a whole, in that not many people understand the depth an answer may require to accurately answer the questions.
A main reason for this is that the specialty equipment required to repair and refinish collision damage (even a key scratch) is available only to shops (usually for zone and compliance reasons).
The very glimpse at a collision related question can determine if it is something that is being asked (and should be answered by) someone in their garage or something being asked (and should be answered by) a structural, non-structural, or refinish technician.
The difference would be something like "How do I get a scratch out of my car?" and "If I can featheredge a scratch in factory paint without breaking through to metal, can I avoid sealer under waterbase?".
To answer the first question you could use about 5 or so 'garage based' answers at about 1-3 paragraphs in length. The same question would be immeasurably too vague for a professional to even start to answer.
The second question would take a professional to answer.
So to the original posted question, my opinion is that they are definitely on topic. My question is - who determines which questions are 'vapid'.