Outlets first so they can route yes. Or pair everything and shut the hub down for 20 min (although I’ve heard that does not necessarily work with Xiaomi). Yes you can and should shut off the SmartThings Zigbee Radio if you’re not using it.
Hue will not interfere if your HE is on channel 13. My first HE hub is on channel 13, The second HE hub is on 20. My Hue bridge is on 25. No issues and they are just 6 inches from each other.
There is one other solution. It’s a bit much for some people, and out of the question for others, but it works and it’s very reliable. The Aqara HomeKit Hub. Link it to HE with virtual switches via HomeKit automations. Works fine for Switches, Buttons, the Xiaomi dual relay, Contact sensors and Motion. Temp sensor would be a challenge, and I have not tried the vibration sensor. I was only having recurring issues with the contact sensors, which are solid on the Xiaomi hub.
