Yes. Audio Software is not very demanding. I'm even using an 8 year old Powerbook G4 with Soundtrack Pro, Traktor, Ableton Live and Logic...
If you want to use Adobe Audition I would advice against it. It's effects sound cheap and have few options. Sony Soundforge and still Apples Soundtrack Pro (as part of Logic 9 Studio) are the best audio editors for Mac and have more sophisticated effects and filters.
Note: If you must use Firewire, you have to buy the Thunderbolt to Firewire Adaptor.