Disklavier

I posted a couple of questions on the site and I have a couple of 
answers! plus more questions...

1) First off, I got hold of the DCD1 CD player and hooked it up to 
my disklavier. As has been stated before, I probably can't 
play "Smart" stuff unless I upgrade my memory or change the control 
unit. This refers to playing an audio cd and a floppy 
simultaneously. However, I can play PianoSoft Plus CDs with no 
further upgrade.
2) Someone asked if one could use this type of system to record the 
midi part off a PianoSoft Plus CD alone. Well, you can. Your 
disklavier manual has a section in it on the settings you must use 
to record external midi. I recently did this with the recording of 
Schumann's Dichterliebe. Put it on a floppy and then played it back 
(at a minor third up) etc.
3) Ok - now I have this - PianoSoft Plus is expensive....not a lot 
of opportunities here...anyone have big suggestions about using 
this? Are there other companies that produce music on CD that works 
in this system? What about resources/places to buy or exchange CD's? 
There aren't many in the catalogue.
4) What about this company PianoDisc? Do their floppies work in 
disklaviers? 
5) What about teaching options for this setup for my kids? What have 
people used? The Yamaha software out there on floppy - does it work 
on disklavier?

Fraser