I'm afraid I can't answer your question directly, but both Audacity and Audition natively record wav files; if you open a file recorded in one app in the other, no conversion is necessary, unless Audition bit-depth is set to 32 and the Audacity file is 16, in which case Audition will convert the file on opening. (I don't know whether Audacity can open a 32 bit Audition file.)
However, I wonder whether you are seeing the Audition icon attached to the files? Or are you seeing Audition peak files, .pkf extension? If the problem is the icon, this is simply because Audition is set as your default program to handle wav files, I think. Are you attempting to open those files by simply clicking on the file name, i.e. without the program being opened first? if so, and if I am correct about the icons then, yes, Audition will open to play those files. And, as soon as they are opened, Audition will automatically create those pkf files.
As to your discovery of the "tiny 5 second clips ..." I think others will have to offer suggestions!
What would have happened is that Audacity (for reasons unknown to us mere mortals) splits stereo into mono (if recording in stereo) and then splits the audio into approx. 1mb chunks - I guess that's why it's called 'Audacity'
I suspect that emmrecs is on the right track with the Audition icon/file association idea.
Audacity is on our list of DAWs to support in AATranslator but just not at the top.
Being more of a cheese burger man myself I really can't help you in relation to mac specifics
Did you try opening the Audacity session again?
Edit: Note to self - don't hit the arrow keys when typing a forum reply as random sentences get removed [insert slaps head] icon