Dolphin can extract but not edit ISOs. It also has a hidden feature to play games from extracted folders, but it doesn't work very well. Out of my tests, Mario Kart Wii is the only working game. This breaks on all Gamecube games I tested, and Brawl because it has multiple partitions (or something).
Wiiscrubber may or may not extract files from ISOs. It can replace files in ISOs, but I don't know if it can insert files larger than the original.
Wit can extract and rebuild ISOs, including with larger files. It can also be command-line scripted. However, it takes around 1 minute or more to rebuild an ISO each time.
With Dolphin: Right-click game, Properties, tab Filesystem, then look around.
None of the above tools can patch Gamecube games properly. GC-Tool can patch Gamecube games. GC-Rebuilder can patch and rebuild Gamecube games. Both are GUIs with no command-line interface.
If you haven't already, can you use Dolphin (or Wit if you have it) to extract all the files?
Then open Windows Explorer to the root folder, click the location bar, type "cmd"? Then type `dir /s > tree.txt` without the quotes, press Enter?
If you use OSX/Linux, open a terminal, type `find . -type f -exec ls -lh {} + > tree.txt` and press Enter.
Then upload "tree.txt" to a gist, so I can look at files and sizes. ----
Looking at http://vgost.wikia.com/wiki/NHL_2K11?useskin=monobook , it seems like this game uses prerecorded songs.
EDIT: I changed the commands to also print out file size. This should be useful for looking for fairly large files (megabyte-range) containing full audio recordings.
Never mind, it seems like all data is stored in files 0A and 0B. I don't know how to extract them. All subfolders only contain Wiimote strap, home button, and MotionPlus video.
Can you try installing wszst and run `wszst extract 0A` If it succeeds, run `wszst extract 0B`?
Can you open 0A and 0B in a hex editor and give screenshots of the beginning of each file? (optional: end)
You're not supposed to send ISOs over the Internet. Worst case, I can download it myself. I think that having a disk/ISO will make it much faster for me to analyze stuff (as opposed to send instructions, wait 1 day, send more instructions...)
Don't buy another disk for me.
I only have a week or so of free time left to do miscellaneous stuff like this...