Were all the topics in 1 Corinthians responses to the Corinthians' questions?
Yes. The letter of 1 Corinthians addresses the problems in that local church that they had written to Paul and asked questions about. First Corinthians 7:1 says, "concerning the things whereof ye wrote to me," showing Paul wrote in response to their inquiry.
Les explains that 1 Corinthians was written to deal with the problems in the local church that they had evidently written to him and asked questions about. He points to 1 Corinthians 7:1, "concerning the things whereof ye wrote to me," as making it obvious that Paul is writing in response to their inquiry. He notes that all these things covered in the letter were responses to the congregation's questions, and those questions rested on problems. The Corinthian church was the most carnal and least spiritual of all the churches Paul had anything to do with, unlike Ephesians, Philippians, or Colossians.