The offline audio issue is annoying, but it sounds like it’s just that – not actually a problem, just a annoying thing to deal with that you can probably find a workaround for.
For the audio, check your logging info (selece your audio in the timeline and press Command+9) and make sure that it’s playback rate is the same frame rate as your sequence playback framerate. If it’s not (i.e. if your sequence is 30fps and your audio is 24fps) your audio will slowly fall out of sync as you move farther and farther down the timeline. I’ve sometimes run into problems with this at work and fixed it by trashing prefrences, but that was a situation where we were working with 29.97 FPS sequences and the audio, which was also recorded at 30fps, was accidentally coming in at 25 fps. Not quite sure how to fix it if you recorded your video at 24p and your audio at 30 – might have to do something in sebsky (which I’m not familiar with) or Cinema Tools, or maybe even media manager would work.
-Ben