Quite a list.
1. Use a Wode its a good buy for that.
2. There a several formats to choose from. NTFS is easier to add games to. WBFS is a format the reduces the size of the games, so is useful for that reason.
a 120GB drive would take about 60 games, some are small, 1GB some large 4GB.
3. You can run games from the LCD panel, its easy to use a GC controller, saves getting off the sofa.
I f you Mod the Wii you can install wodeflow, and use like a usb loader.
4. If you softmod you can install wimc to show videos/movies
5. You could use the site sponsors, vancity mods, mod chip depot