I would love to be able to download CC directly from the gallery, but any such option would have to be done in a way that you don't accidentally download something (by for instance downloading a lot or a sim that has CC), but instead by downloading the CC itself (the same way we do on websites today). That way it's easier to get for those of us who want it, but easy to avoid for those who do not.
I also second all those who mentioned that an easy way to link to used cc should be present, so that it's easy to find cc you like and give creators credit when their stuff is used.
However, what I want more than being able to download through the gallery, is an easy way to uninstall CC from within the game. Many times you download something that looks awesome on the website, and then it renders horribly in your game. To then turn off the game, find the right file, remove it, open the game again... Especially CAS items are hard since you cannot see their names in game (unlike bb-objects). At the very least adding the names to the CAS sites, so that I know which file to remove if something is broken or just not to my liking.
Another thing I would really want is the option to filter out cc-content from build/buy-mode as well as CAS-mode, similarly to how I can filter away packs. Today I can filter away everything but cc, but not the other way around (only keep EA-content visible). Sometimes you want to use cc and other times you really don't. I would also adore an option which in build/buy-mode highlighted cc-objects so that I can easily identify which ones they are and quickly remove them if I want to.
