Mounted and loaded ipod under Rhythmbox, saw all files. Tried to play music, failed (sound was not configured correctly). Failed to exit rythmbox cleanly.

Next time that I tried to access ipod, Rhythmbox only saw the songs which I had purchased, not the entire contents of the ipod. I dis-associated rythmbox from the ipod in gnome, mounted it, and loaded the ipod under gtkpod. Gtkpod griped about checksums not matching the ipod control database, then re-wrote database using sha sums of the songs on the ipod. This worked, apparently; I was once again able to see all songs on the device.

I ejected the ipod from gtkpod, then opened the ipod again in rhythmbox; I only saw the purchased songs agin. I'm not sure exactly which steps I took from there, but eventually I figured out that if I launch rhythmbox after I load the songs in gtkpod, rhythmbox will see all of the songs on the device, and I can play all of the songs except the purchased ones, which remain encrypted.

Questions:
1) Is the ipod control database cached somewhere in rhythmbox? If so, I'm guessing that this has gotten corrupted somehow. I would like to be able to have
rhythmbox start fresh with my ipod. How do I clear this?

2) What is the current state of the art in terms accessing purchased files on the ipod? I tried loading itunes via wine, this failed. I wouldn't mind burning files off to CD then re-loading them (I haven't bought that much off of itunes, and MusicBrainz Picard does a good enough job re-constructing the meta-data).

3) Does anyone have any experience with either Rockbox or ipod-linux? How good is the user interface? What are the chances of bricking my ipod?

I suggest gtkpod. Some time ago with Debian Testing, I had a problem which on hindsight I think was due to the device being mounted automatically with a mountpoint unsuitable for gtkpod:
http://www.linuxquestions.org/questi...highlight=ipod
I don't know about your specific problem but found that I was able to move files in and out of the ipod through gtkpod.
It was possible to move files in and out using cp, on commandline, via the mountpoint. If you do this you will find that the names assigned to the music files are in code. This will only be of use to you if you need to "rescue" music from the device.
I can't say for sure that you won't damage your ipod but the various ipods I worked with, including a nano, survived all my experiments without damage.