I may just picking up parts of it, but yeah...
1. EA never paid for this project that started off as a mod and is thus not a part of EA's projects pipeline. This small gem here is based solely upon the license of C&C and thus EA. Nothing more. (Except Renegade) The rest is made out of the tears, love and body parts of the devs, providers and testers. As far as I know this started at a point where EA was still kind of public-friendly and didn't really mind free CnC Projects.
2. Free. Yup, completely free. As in "Download it. Have a great ton of fun. Play it."
3. They needed to make it free. Otherwise it would be kind of a Copyrightinfringement. And honestly, I don't mind it as free project. It's a great piece of advertising for the devs themselves if they want to start something in the game industry.
4. And it's based upon the UDK because it's usable for free for free projects. It's nearly the same thing for the CryEngine. For non-commercial projects it's usable for free.
5. As explained before... It's kind of different for the UDK. As far as I know there aren't any plans for UE4 as they had made with the UE3 and the UDK.
6. Shouldn't be. Except some self-advertising for Totem Arts
That is so far my explanation. Hope you don't mind it.