Well the answer to your first question is no.
The answer to your second question is maybe. The key to messing around with changing default switches on a JR radio is to first go into the system menu and inhibit everything after the first four channels. Then create a mix from the flap switch to the side lever and see if you can make it work. It's been too long since we setup my KingCat on my 12X so I don't know if you'll be able to use the flap system or not, you may have to just mix the two channels and assign them to the lever.