The first option will mean lack of control from the rider, and so most people will probably not like it. The second is technically feasible, but somewhat complicated. The easiest implementation would be to have the derailleur adjusted by screws similar to how it is now, and just have the shifting done through a device that shifts upon receiving a signal transmitted without wires. Again, as I said, I don't how how it is actually implemented and what level of sophistication is involved.