Thanks to you both for the feedback.
I'd really like to be able to say "I'll get right on fixing those things and making it better!" but as luck would have it some yet-to-be-tracked-down piece of hardware on my desktop bit the bullet not four hours after uploading this, leaving me with a hunk of useless metal and plastic Here's hoping all my premix tracks are still intact... Likely its a sound/graphics card or power supply/motherboard issue, though.
But that's okay; keep them crits coming. I can still read and think about ways to improve the mix while I'm playing geek squad