Disklavier

I am the proud owner of a DA1 II Disklavier Grand Piano.  Since 
this is a Mark II piano I would like to upgrade to a Mark II XG 
capability.  If the DSR1 Upgrade Kit is used (1) will I be able to 
use HD Floppy's or will the upgraded unit require DD Floppies only? 
(2) will two of the unused Mark II buttons (Repeat, "0", Disk) be 
modified and designated as new Mark IIXG buttons (Voice & Balance)? 
(3) if I also purchase the DCD1 CD playback unit, can I use the Part 
Select buttons (L or R) to disable the piano track from the CD to 
allow me to  become the pianist for the musical piece with full
orchestra background (as is provided by the Mark III series pianos?

I am also considering using a Third Party Mute Rail System to cancel 
the acoustic piano sound and allow me to play into headset or 
speakers.  Does anyone have knowledge of this modification, pro and 
con.  I am trying to achieve as close to a Mark III update as 
possible.