One thing it *doesn't* do is prevent the device from contacting the TP Link servers nor NTP servers all over the world. Turning off remote access only stops *you* from accessing your devices, TP Link...

Connecting the red to ground is definitely wrong and probably dangerous. Connect the TP Link green directly to the electrical box which are usually properly grounded. This looks like 3 way switch...

Nothing will change, that simply bypasses the HS200's relay.

There appears to be a command for it, I'll add it to AutomatoinManager for anyone that has it and wants to try. It'll be in the next beta version.

I don't know much about electrical regulations outside of NA so for all I know that might be normal, but it looks very dangerous to me. My guess would be TP Link is only using a single relay to pass...

Yes, you can chip out the drywall until the switch fits flush. It will be flush against the box in normal installations. Just be sure not to damage the drywall past where it's covered by the plate.