A:AnswerYes it can, and its works great and is a nice feature. You just need to link up wemo/google via google home app. Also make sure you name your Wemo switces in a manner that it's easy to speak and understand. Example: "Hey google, turn on Living Room Lamp."
A:AnswerIt operates like a regular switch, just programmable, so I would think it would be perfect. With a Google Home or an Alexa, you could even do it with voice commands, like "change pool lights".
A:AnswerYes you can. And its awesome! Create a section in your Alexa app and include this switch to make it easier. That way you don't have to ask Alexa to tell Wemo to turn of the kitchen light. You can just say turn off kitchen lights. Make sense? lol
A:AnswerBy default, no it does not work with HomeKit. If you look into something called homebridge for apple home kit, you may get what you're looking for.
A:AnswerYes, as long as there is only one switch controlling both lights. Two way switches in which you have two switches controlling the same light(s) will not work with these.