Hello Skeezix
I have the PSR 2100. I can answer your first question: The board was trimmed down due to an accident when we moved to a new server. It has not been possible to retrieve the posts. So now it is ut to us with the old keyboards to write some more posts
Sadly, I don't have the answer to the other questions, but I guess others will chime in soon.
I am curious: Do you still use floppy disks, or have you installed an emulator?
I still have the floppy, but I rarely use the 2100 any longer, as I have two newer keyboards. But the 2000/2100 are fantastic keyboards with good sound, and they are built like a tank, sturdy as can be. I will never part with mine. When my S970 suddenly broke down, the 2100 served me well again for some months! Good luck, and take care of the 2000!