Thank you both for taking all the time to think this through!
Continuing backwards: I'm running the Core Audio bus to headphones or a bluetooth speaker.

- About my Mac
- Screen Shot 2014-07-05 at 6.50.49 AM.png (54.47 KiB) Viewed 1420 times
I'm not working with a DAW right now, so no associated latencies, etc... this is all next level wtf to me.
The issue with Apple's AU's is also quite bizarre. Some of them do seem semi-functional, I'm discovering that it's the preview that kills the functionality: if I don't preview, I may be able to make some adjustments and hit Okay, and it may work for some of the units; but once I try to preview, the settings can no longer be changed- the sliders can move, but the numbers won't change until I cancel and try again. So I may be able to apply them in a more blind fashion than usual. I've attached some crash logs here (archive.zip) but I'm not certain they're related directly to the issues discussed in this thread.
With regards to system access, it's a little tricky. This is my work computer, and I'm a cardiovascular biologist who spends most of his time these days in front of a variety of microscopes, with no sound, whatsoever... and we're not supposed to install our own software. I have super-user Audacity on my PC at home, but I spend so much time on this Mac it's just... i don't know, i can't be picking one up, putting another down, computers are, like, heavy... well, it wouldn't hold up under interrogation, or, really any conscious thought, but by the time I actually have the free time and means and environment for leisure (hobby), it feels like a truly prohibitive effort to get my own computer.
I swapped up to the Retina from a MacBook Pro this Spring, and ran into some trouble with my setup, as I mentioned. A majority of plugins crash the program now, but I really can't complain, my lonely user install has worked very well for several years; there were some plugins I couldn't try, since they needed a system installation, but there really was a lot that could be used until [presumably] Mavericks. This wobbly playback is really starting to wear me down, so I'm going to unplug for some time, until I can re-assess. If I'm able to find anything out that may be of relevance, I'll post it. Hope everyone has a great holiday, weekend, day, or night, depending on your inclinations. Thanks again.