1. You would have to desolder the LED, desolder the switch, solder on the new switch, then resolder the LED, as many times as there are keys. Not fun. (Pics of the switches below)
2. Neither. A Filco ZERO Tenkeyless with white ALPS would be my pick. But if I had to pick one of those two it would be the deck just to try the black cherrys.
3. I'm with bhtooefr on this one. It would make sense an ergo board would have a lower activation force (Cherry Ergoplus, Model M15, etc)