Well, what I know is that Nintendont list sd media launcher .iso and launchs it just fine:no , nintendont does not run any gc homebrew, nintendont works by patching sdk functions and patterns which games use, homebrew has no set rules for patterns so nintendont cant patch them therefore no homebrew runs at all
nope nintendont doesnt run any gc homebrew, due to how nintendont works.
also every gc homebrew has a wii version so why would you use the inferior gc version over the wii version? i have no idea.
I don't know if from there you can use gecko like you said, because i don't have one. Was a shot in the dark.
What I know: You can use gamecube homebrew in the wii, but in other ways like dios mios, and neogamma (if compatible wii disc drive)