The way this works with Z-Wave is slightly different.
Indigo maintains information about all devices within its database "independent" of the Z-Wave stick. If you have access to a Windows computer, there are free tools you can use to backup the stick (there are other ways, but Windows is the most straight-forward). If the stick were to fail (or you want to upgrade it) you restore the data from a backup of the stick and Indigo motors happily along. If you don't have a backup of the data, you must re-include each device into the new stick and then associate each with its corresponding Indigo device definition. In other words, open each Z-Wave device in Indigo and pick its new device number. Not a big deal for smaller networks, but larger networks make backing up worthwhile, IMO. In either scenario, you don't lose any actions, schedules or triggers associated with the Z-Wave devices once the stick has been restored.
To free up unused addresses, select "Remove Failed Modules From Controller" from the Z-Wave menu. Sometimes, the stick doesn't want to release them so easily however. Then you need to attempt to create a new Indigo device with the failed address as the target. After Indigo fails to include it, you should then be able to free the address using the first approach.
You can upgrade the firmware of both the stick and many Z-Wave devices using the tools mentioned above. I have never found a need to do this (although there have been some new Inovelli firmwares that look interesting).
You can find more information here