I wouldn't want to use the TP Link (or any other IoT vendor) cloud to monitor/control mission critical devices, there's too many moving parts out of my control. Most aquarium users I've known...

He's got a camera plugged into the socket, and wants to power cycle the camera when he's away from home. For that he would use Kasa and needs remote access enabled. If you can't reach the plug to...

Well, no, it's still more than a "normal" switch even without a cloud account. It can still be automated. You folks (the vendors) are happy to gather and control our data in your cloud servers, but...

Nope. You might find lan connected relays on ebay, but most IoT vendors have switched to wifi as they can be deployed more easily. Would WOL be more appropriate for this?

You need the neutral, if you're using a GFCI you must use the line in and neutral from the load side of the GFCI. It's a bit difficult to tell from your drawing but that looks like power through...

Pat's reply is spam, it's probably best not to follow the link.