Actually, you do not want to be classed as a real estate professional, because your property will become inventory, and you will not get the long term capital gain provision under the law. All you need to do is show that you are managing your own property. You should have a log of daily travel mileage to your properties. Do not worry. Do not volunteer any information. Make your answers short. Calm down. Your fears can work against you. Let them make their adjustments if any. Do not give them any personal information, like cost of living or personal check book. You did separate your business from personal checks in a separate account didn't you? Whatever happens, after they make an assessment, if any, you can always get a CPA or Enrolled Agent to appeal the assessment.
CPA and retired tax auditor.