I'm not too sure! It's a possibility but I didn't take it apart to have a look. Do rubberdomes have the same pinout as MX switches?
No, you would need to run wires to each switch and then run them back to the circuit board. I assume there is some sort of connector between the RD and main board. Would be quite a challenge, but possible. But again if the switches wouldn't fit, it would be a show stopper.
If I ever see one for cheap, I might give it a go...