Do you have Soundflower or other audio programs running in the background when Pr crashes?
Do H.264 .mov files with different audio specs import OK?
Can you use Quicktime to demux the audio and video into AAC or AIFF audio files and Photo-JPEG or PNG (visually lossless) MOV files?
Warning: my MAC experience is somewhat limited and outdated. I can use Quicktime Pro on Windows to demux MOV files like I described.