Every SDC Address has a new private key, however because this SDC Address was generated by sending coins to a "stealth address" aslong as you have a backup of your wallet when you created the stealth address you do not need to back it up again. All future SDC addresses created by sending money to that "stealth address" are covered. This is a bit like a HD wallet but not quite ...
Obviously you can never be too careful so backup as necessary.
It seems like over time I will have hundreds of keys and stealth/public addresses in the wallet.
Yes but as per above, if the funds where sent to a "stealth address" then it does not matter as you can re-create those SDC Addresses and corresponding private keys from your stealth address backup.
Okay thank for the help.