Why even have the breakers off in the first place? Just leave the devices on or turn them all on at once. You want them all to find each other so they build out the neighbors.
Just boot up the C7 and let it sit for a short while, then I would run a full repair to give a kick start at finding all the nodes and routes. A lot of nodes might fail the first go around. Maybe give it a couple of hours and then try the repair again if a lot failed the first time.
Make sure your Z-wave firmware is up to date on that hub. If you have an "Update Firmware" button on the z-wave details page, then you need to do an update.
It should all sort itself out, just be patient. It might take a couple of days for all the devices to work out routes, depending on how scattered they are. I feel like it would be best to just power them all up at the same time.