I move the files into sub-files so that only what I'm installing at the time is visible.
No, you should NOT move the ccmerged file. It is the one file that stays. All the premium content installed adds something to that file and your premium content will not work without it.
I do make a sub-folder for everything installed in the dcbackup as I go along. Why? Those files can go directly into your mods/packages folder and work as cc in your game if you ever need to reinstall, but the launcher won't work. (Some time in the future, the sims 3 store will close and the launcher might not work as expected after that. It should, but... this would be a precaution.) Also, some people install the store content through the launcher, but then move it all to the mods/packages folder so they have no .ebc files or .dbc files for cc in the launcher. They can merge several package files together taking up less space. And, the launcher is left empty so it has less work when uploading, downloading, and starting the game.