Let's see.....
1) There are 3 sounds available for the right hand at any given time. They are on the right side of the screen, and you access each sound by pressing BOTH buttons next to the sound name. The balance is handled in the mixer section.
2) The hard drive command for adding data is "Save". You save to a folder like in a windows envirnment.
3) I haven't used a dedicated volume pedal yet, by Roland and Korg SEEM to play well together in other areas. Try an EV5. I used to use a vol ped all the time, but since making the switch to a standing position...the less on the floor - the better !