What type of modded play store do you have? Just a slightly modded (themed), hacked (reverted to older version, disable play store from updating)?
Cwm comes in when your interested in flashing roms, through cwm you can make backups of your current rom which is an exact snap shot of your current phone. You can restore that backup in case something happens you don't like. The restore will put your phone to how it was when you backed it up.
Superuser is an app mainly for the apps that requires root access (any time an app asks for root access, make sure you trust that app before granting)