These are delivery specs, for the final output, rather than acquisition specs, which would dictate how you would shoot it. I feel like these specs aren't presented intuitively, however, so I'll only answer what I'm confident in rather than give mis-information.
1.Composition size is the export resolution. The resolution of 432x252 provided is definitely not HD, so that seems confusing, and is actually a 12x7 (1.714) aspect ratio, so be sure to set your editing timeline accordingly. You may as well set the timeline resolution to that size and scale the footage down so there aren't any aspect ratio inconsistencies once you render.
2.Things to consider during production would be the delivery aspect ratio (12x7) for framing while shooting, and the framerate, so yes go ahead and shoot at 30fps to avoid any framerate mismatches.
3. Video bitrate is set at export (depending on the codec), and I'm assuming they're meaning at least 9,000kbps, or 9mbps. I'm not sure how the XVID codec they're asking for handles bitrates, I've never used it. The 24bit rgb color depth is also sometimes called 'millions of colors' and is a default for many codecs.
4. Final Cut Pro does not natively support exporting XVID or AVI files. I would suggest exporting in a different codec, and using a different encoder to export the AVI in the XVID codec. In my quick limited research just now, it seems XVID and AVI are more Windows based formats, so you may have trouble with a Mac.
Edit: I see they also accept h264 MOV's, that will be the easiest format for you most likely.
5. I believe so.