Thanks for your answer. Do you know if there is a "save as" type command in Logic that would allow me to save the 9 files down to a 7 version (as there is, for instance in MS Word), or would the best way to exchange files be between the 2 programs, would be to export them as audio wav files (or whatever command one would need to do that)?
Do you know if there is a "save as" type command in Logic that would allow me to save the 9 files down to a 7 version
There is no such function in Logic.
Your best solution depends wheteher you need to keep any MIDI /Software Instrument tracks available in the transfer.
Logic 9 has 'Export all Tracks as audio files" functions, which would allow you to create audio files that could be imported into v7. You may also need to export a MIDI file (possibly with any MIDI parts) to get the tempo/Time signature maps.