Absolutely none of the assets can be used in a for-profit product. I wouldn't recommend using any of the assets since essentially all of the assets belong to the individuals who made the assets. In addition, many assets are subject to EA's intellectual property rights for Command & Conquer, meaning we can't authorize you to use them at all beyond Renegade X. In shorter words, no, you can't use the assets without permission from whoever created that individual asset.
As far as code goes, the situation is similar in that individuals still own most of the code which they contributed to the project. With that said, I don't really care if you use anything that I've personally written. However it's very difficult to figure out who wrote what, and the only parts I would be totally comfortable saying you can feel free to use however you like are the repositories (Jupiter, Jupiter Bot) already ISC licensed on my Github profile. Those aren't part of the base game though; they're external applications.