If I have all (well most, like 90%) of my rules, apps, etc on my C4, but all my devices are actually in a linked C7 hub, Do I still need the stick on the C4? Or can I remove it from that hub and disable the radios on it? I am thinking I should be ok to do that but wanted to ask.
It sounds like your C-4 no longer has any Z-Wave or Zigbee devices directly connected to it. If that is correct, then, yes, you can remove the stick(s) from the C-4 and disable the radios in Settings. Hub Mesh and HubConnect are, from the perspective of the "shared-to" hub, ultimately just LAN (or cloud if you use that option in HubConnect) integrations, unaware of the protocol(s) in use on the "host" hub.
Correct, there are no devices paired directly to the C4. It just handles the rules and processes. The devices are all connected to one of 2 C7's (I have no idea what to do with the other). I was using hub connect, but when I changed my router it stopped working and I couldn't figure out how to fix it, so I removed it and switched to hub mesh. Seems to work for what I need.
To be honest, switching out that router caused a lot more grief than I was expecting.