You can be pretty confident that the reason the Gamecube game doesn't play is because you haven't installed the cMIOS, so any further attempts will meet with the same result until you rectify that.
Ok, ret =-1 nearly always points to a missing wad file. The installer you are using needs to have the wad file in a specified location or it will not install.
Things to do:-
Check you have the wad copied to your Sd card.
Check the wad is the correct one for the cMIOS you are hoping to install.
Check you have copied the wad to the correct location.
If the installer offers you the options between Wad Install and Network Installation choose Network.
CMIOS and cIOS installer tend to come with readme files which can provide you with clues how to get them set up correctly.
Here's an example I found on the web..
Good luck --->
- Copy "RVL-mios-v8.wad" to the root of a SD card.
- Insert the SD card on your Wii.
- Run the installer and select "WAD Installation".
- Run the installer and select "Network Installation".