Export full-quality AIFF files out of GarageBand
Yes, you can:
Hide the Podcast Track (via the Track Menu) and the project will export as a 44.1K/16-bit uncompressed AIFF file.
Just make sure to uncheck “Compress” and it will export as AIFF.
A good tagging solution? Haven’t found anything decent enough. I’m using iTunes, because every other solution that I tried was wonky. Most apps have problems setting Podcast tags correctly, so they’re recognized by iTunes. The only solution that I found to this was, well, using iTunes. (As painful as it is for some of you…)