A suggestion for the installer.
I'd propose for the 'custom' interface, the ability to load one of the presets.
For example: I love a lot of your music choices on your recommended list, however I can't get behind your choice for The Mystic Forest. It's a great track, but it doesn't quite fit the feel of the original. Likewise, I feel your choice for the World of Balance theme doesn't quite fit the tone of the original - great song, but it gets way too slow at points. This basically means I am left with manually subbing tracks in the file system or creating a whole set of songs for the game one song at a time. It would be much better if I could go 'I want the Developers Mix, but with these few songs changed'.