Any way to be able to record into audition while also playing back files in audition?

The words you are using don't entirely make sense - what exactly do you mean by 'output files'? Are you talking about files that youv'e already placed in a session? When you have a file in an Audition session it will automatically play whilst you are recording another one - unless you prevent this from happening by muting the track. Is this what you mean?