1. Hacking a Wii is different than the two consoles you mention, but accomplish about the same thing, playing backups.
2. Yes you can unhack your Wii, but there will be traces left behind.
3. why would the list lie?
4. backup discs play at 3x, retail discs play at 6x, and usb loaders play games at 8x
5. Good luck making backups of your old cartridges, CleanRip will backup your GC games. There are emulators for older systems (DON'T ASK FOR ROMS HERE), the Wii will load backup GC games, from disc, as long as you don't have a D3-2 drive installed. Look in my signature for that. Look to the Wii Drive Chip Database.
6. Hacking your Wii is easy, why have your friend do it, after all you said "I am pretty decent with computers", it don't take much more.