@Odonata68 - Yay! I'm glad you finished your install and backed everything up. It's such a relief when you finish and know you don't have to do that ever again (unless you change your install from DD to disk or Origin to Steam). Congrats to you!
And yeah, I always got so very bored on those installs. I'd take breaks after each major hurdle and often forget I was installing and get side tracked. So, I'd usually take a few days installing everything myself.
@Goodywood - You should be able to get that all in one file.
I'd install the patterns and then move the dcbackup folder files into a new sub-folder called patterns. Then, I'd install the wallpapers and move those dcbackup files into a new sub-folder called wallpapers. You can't tell what all the little files in the dcbackup folder are, so moving them into a sub-folder as you go will let you keep items grouped by set. The dcbackup files are only supposed to be required for cc items, so many just delete the item files and only keep the ccmerged file where the premium content adds info to this file for animations and moodlets to work properly. I think you might want to keep them, if you have room, for at least the special items that cause problems in uploads like patterns and maybe the premium content items.
Just copy the .ebc file before you install another item (if you think you might go over in size when you add another item). That way, if you do go over 204,800 kb; you can delete the file that got too large and revert back to the old one.
Good luck!