The problems you're having with the mic are not really problems with the mic. Unless you are using a fancy multi-track recording set-up, Apples only handle one audio input and one audio output at a time. Sounds logical, right? I assume when you plug the mics into a hub, the Mac recognizes them all and wants you to choose one, just like it would with a scanner or printer.
If you need to use multiple mics, you should get four mics with XLR connectors and a small mixer.
I recorded a podcast or two with the Samson around Thanksgiving time when we were out of town. To hear my results, check out:
http://www.danklass.com/pill/BP20051121.mp3
I used the USB mic, a software compressor and a foam pop screen. I wouldn't say it sounds as good as my "studio" mic, but it didn't cost as much either and is MUCH more portable.
Best of luck -
Dan Klass
The Bitterest Pill
Apple G5, iBook Mac OS X (10.4.3)
Apple G5, iBook Mac OS X (10.4.3)
Apple G5, iBook Mac OS X (10.4.3)