Fix SQL SELECT Errors -- 2

My database is returning errors on several basic SELECT statements and I need a fresh pair of eyes. The tables are already in place, but the queries either fail to run or return unexpected results. Although the current environment is MySQL, I’m happy to apply a solution that would also work in PostgreSQL or Oracle if the syntax is kept standard.

Your task is to review the problem queries, identify the exact source of each error, rewrite the statements so they execute correctly, and give me a brief explanation of every change you make. I’ll provide the schema, sample data, and the faulty statements as soon as we start. Clean, well-commented SQL and a short summary of fixes will mark the work complete.