OKay, I'm no expert but ...
It's not going to be easy if you stick to the original case/hardware ... so youd need an external box - not a problem.
Backing up games has been done - I have no idea how, and don;t really care, but it's been done!
To stop the physical protection get an external DVD drive and wire it in place of the mini drive that's in there ... similar to replacing the Xbox one. This will hen read the correct media. There will have to be some gubbins to convert the signals from one to another, but not impossible. This is the hard bit. If someone was really clever they could even use a HDD instead (similar to the N64)
Then need a mod chip to remove whatever software protection there is. Every other system that i can think of has been chipped ... so the Gamecube can be too - I should imagine this is the easy part.
Then stick all 3 together and hey presto.
I'm not an expert at this, but the Xodus or XEcuter teams obviously are.
All I do know is that and chip will be popular and make the designers a LOT of cash
