If there aren't any z-wave devices attached to your hubitat then you won't have any ghosts to remove. You do have to exclude any z-wave devices from previous hubs to pair them with hubitat (you can use hubitat with the exclusion) but if you get repeated failed pairings you need to factory reset the device you are trying to pair. This isn't a hubitat thing, it's a z-wave thing.
Hue, Cree, and the like are zll based zigbee bulbs and should be on their own mesh. If they are on a Hue Bridge leave them on the hue bridge and use Coco Hue from the hubitat package manager to connect hubitat and hue. The hue bulbs will then be put on hubitat that way but kept on their own mesh.. If Hubitat is having problems communicating with your Hue Bridge and they're on seperate vlan's you will have to alter your firewall rules to allow them to talk to eachother.
I also recommend in your DHCP server, create a reservation for Hubitat and your Hue bridge so they don't lose eachother and you don't lose dashboards to HE changing it's ip address.
Any zigbee devices you have have to be factory reset to join to Hubitat or they will stay joined to your old hub.
There is a community nut driver available I believe. [DRIVER] NUT Discovery + UPS & Outlet Status
