You will not need to reinstall your game. Actual mods that change the game's behavior but do not add objects to it would not need to be worried about.
I do believe you would need to reinstall all of your store and custom content, both sims3pack and package based, in order to restore those files. If you deleted the ccmerged.package file along with everything else, then none of your store premium content (if you have any items that fall into the premium category) will work and those will need to be reinstalled even if you choose to not go through with the rest of it. Although you could also use a known to be working ccmerged file
from here if needed.
Besides the ccmerged file though, having deleted the other contents of DCBackup would mean that exports for other players to use would no longer have the CC attached as you said. Many of us do not routinely or even ever prepare such sims or lots for other players, so we do prefer to keep DCBackup free of all that clutter other than the one required file.
