If you already have the devices enrolled in the module then these will automatically populate when the initial syncing of the system is complete with Alarm.com.
Yes, the module has a single control button for adding/removing Z-wave devices as described in the linked instructions.
A Network Rediscovery maps routes for Z-wave devices already enrolled in the module. It does not discover new devices.
It looks like you do have three devices now in your Z-wave device list, two locks and a thermostat. We can send a Network Rediscovery on request for a Concord 4 panel. Send us a private message if you need to request one.