To install to the internal HD, do I just put in the disc and run Rogero? I personally prefer Multiman, since it plays games from either External or Internal, even though other BM force you to load games on the Internal!
How to install to an external HD? I think you copy them via the O-button and then you can choose where you want to copy the game. At least it is like that with multiman and Gaia...
The External HD should be FAT32? Yes.
What would the folder structure look like for the games to work? I have all my games on the folder "Gamez" but I think "Games" does work as well.
Can I install and run more than 1 manager like on the Wii? Yes.