Uh, so why does your thread title specify "Additional Content"? The Additional Content is just an item that opens a folder with bonus wallpapers and such.
As for the other games...
A lot of the games have been upgraded with community-created unofficial patches that fix a lot of their bugs and compatibility problems. You can find them here:
Command & Conquer 1:
Red Alert 1:
Tiberian Sun:
Red Alert 2:
Generals:
Renegade:
The games simply have their problems... it's just general "old games on new systems" issues. There's nowhere else you can buy them that will make them magically work better, especially since the DRM of the original CD versions is no longer supported by Windows itself.
I'm just a volunteer here who knows a lot about getting these games running, though. If you choose not to play the games at all, just because you don't want to look into the available community patches, that's your own business, but, me just being a volunteer, I have no idea how Origin's refund systems work. You'll have to figure that one out yourself, sorry.
