1. When recording multiple tracks, can you assign different effetcs to the various inputs? In other words, a stereo guitar part with different amp models as well as a vocal part through a microphone.
You can record up to 6 tracks simultaneously, but I'm a little unclear on using multiple insert effects. I think you can change an insert effect on a recorded track, but then you have to bounce the track to make it permanent.
2. Do either of you use the USB connection? If so, can you back up raw, unmixed tracks this way as well as mixed down material? Does the USB allow transfer the other way so I can take tracks from a CD and load them into 2 tracks and play around with them?
Yes. You can download an audio file manager program from Zoom's web site. Using this program, you can convert tracks to wav or aiff files. You can also convert a wav or aiff file to a v-take. With the USB connection, the zoom appears as another drive on you computer, you can copy files back and forth. You can also copy midi files from your hard drive the zoom.
3. If you use the CD burner, the same question - can you back-up raw data so you could go back later and remix?
Yes.
4. How are the effects? I am interested in something simple to get my ideas down w/o a lot of hassle, so the guitar effects are key.
I've heard a lot of people say the effects are a little over the top, but they can edited to suit your tastes.