I've seen noted elsewhere that sometimes when people manually extract the addon, it doesn't quite go in the right place.
For example, the 3 Carbonite folders should be extracted into the addons folder itself. I don't use Macs so I'll borrow your folder structure you posted. It should look like this
applicaitons/world of warcraft/interface/addons/Carbonite
applications/world of warcraft/interface/addons/CarboniteNodes
applications/world of warcraft/interface/addons/CarboniteTransfer
What some people have seen when they extract is it comes up like this instead, which will not work:
applications/world of warcraft/interface/addons/Carbonite/Carbonite
applications/world of warcraft/interface/addons/Carbonite/CarboniteNodes
applications/world of warcraft/interface/addons/Carbonite/CarboniteTransfer
I don't know if that is the case for you, but it wouldn't hurt to look