Hubitat does speak to Nest products, and at this time does not speak to Ring products directly. Hubitat does work with Z-Wave smart locks.
About lighting/shade solution: You can't go wrong, IMO, with Lutron Radio RA2. I have a RA2 system in my house, and it is fully integrated with Hubitat. I use RA2 motion sensors throughout the house, even in rooms that have Z-Wave dimmers instead of RA2 dimmers (house is half each). There are special integrations for RA2 keypads, making them smarter -- "elevated by Hubitat". For example, the keypads don't just turn on a scene, they set the dim level of the scene that is appropriate for the time of day (something that RA2 cannot do on its own with separate keys for each level). I've also integrated the RA2 VCRX garage door controller into my system. The garage doors have separate Zigbee sensors for open/closed sensing.
You wouldn't have any trouble with things like turning off all of the lights downstairs with a Lutron keypad -- that's basic functionality. But if you add motion sensors, then you don't even have to touch the keypad, they can just turn off automatically. Hubitat would actually give a command to the RA2 system to do that. Hubitat connects to RA2 over the LAN.
