So, you added all the repositories and you open Application Manager and you go to the section called Browse Installable Applications and you go to each one and click the Information icon at the bottom and it says Installable and then they don't install?

Is that what you're doing?

If not, do that.

If that isn't illuminating, delete all your repositories. Then go back to the wonderful repository site mentioned above and add them all back in. Then do what I suggested above.

And if that isn't illuminating, reflash.