Hey Joemarc, how's it goin' - have you tested the mod yet? No pressure of course!
About the XCC things - they are vital to any sort of decent YR/RA2 mod. With the XCC Mixer, you are able to view the various .mix files used by the games. You can then extract the files inside the mix files for editing - this is where you rulesmd.ini file comes from, as well as the artmd.ini file, all the game art, sounds, voices, movies etc. etc. You can then put your edited versions back into a mix file, place that mix file in the RA2 directory, and away you go
The XCC Mod creator makes things tidier (and easier). Once you have created your mod files, you simply drag and drop them into the various sections of the program. You then select Export from the menu - and this creates an exe file that will launch your mod, meaning that you won't have to play around with files in the game folder.
Well, those are the raw basics. For more info on Olaf's XCC thjings, go to his site at
http://xccu.sourceforge.net/. There are also a few modding tutorials there. I know a few tricks with XCC Mod Creator so just ask if you're in the dark
And about superweapon editing - I remember I changed a few simple things like more power to the nuke, longer lasting time for the weather storm, screen shaking when nuke hits etc. but I just accepted the fact that I should leave the supers alone if I don't want headaches
Don't let that put you off though, go and read that sticky topic on the main page for lots of superweapon editing info. If you want to change some paradrop stuff though, consider that much easier