Disklavier

I have a DGH1BXGII w/DCD1.  I would like to move the control to 
another room (Piano in loft, control down below).  Question is 1) Do 
I need to be concerned with the length of cable going to piano?  I 
figure it to be approximately 100ft.  2) Any experience with plugging 
DCD1 output into whole house audio system?  Would like audio in home 
amplifier vs. powered speakers that I am currently using.
Bryce Custer