The price is low

Low enough for you to replace the engine/transmission/turbo if needed?

If not, walk away.

XR500 with OpenWRT installed.

Found my used one for $10.

Oxygen reacts with the oil. That is why you need to change it due to the time it has been in the engine.

Lunch and a short meeting of what you’re expecting from the team would be a great start.

My question is what stops the devices that are integrated with HA from talking to some random cloud server) ?

You can use your firewall/router to stop any if your networked device to go to the internet.

Home Assistant can do that, even across different make of products.

NVR?

I use as much Tasmota/Beken compatible smart devices as I can. I avoid cloud (someone else’s computers) as much as I can.

Location matters here as EU plug is different than US plug.

https://www.youtube.com/c/TheHookUp

https://www.youtube.com/@SmartHomeSolver

I have cameras pointing at the street where the garage cans would be.

Does the NVR not provide a web site you can see the footage?

Wire one switch physically to the lights, have the other two switches mirror the first switch is what I would do if I have it my way.

I use Tasmota and Home Assistant so I can do that.

My smart switches add functionalities, as if my Wi-Fi is down, I can still turn on my lights by using the light switch themselves.

I don’t use smart bulbs.

Also, is wireless better?

Wireless is definitely better than drop frames, lose network connection, lose audio, and etc.