The best way to export Test Cases with their Steps and Expected Results would be using the Excel Add-In. You could select Test Case Step as the query type, then
type in (copy & paste) the following columns for the information you are looking for:
CreationDate,ExpectedResult,Input,StepIndex,TestCase,TestCase.FormattedID,TestCase.Type,TestCase.WorkProduct
You will want to filter on certain test cases as needed.
You can find more information on the Excel Add-In here:
http://help.rallydev.com/rally-add-excelEDIT: one has to TYPE these fields into that column field, as they are not available for selection