4. When using USB Connection I get unwanted high pitched noise through Amp.
This is almost certainly a ground loop. You could try plugging the PC into the same socket as your audioi, or maybe a USB isolator if it is an issue.
5. Midi Signals are disabled while USB is Connected, my H9's are a part of a system. I do not want to disconnect them to test programming changes.
Sorry – this is a hardware limitation – nothing we can do.
We are talking to Mr. Liquid Foot at the moment – hopefully things will come of it.