it's okay if you're a novice, MIDI is strange thing to get around, especially if you're old school, used to straight multitracking.
i'm not sure if this is what you are doing, but from your post, it seems like you're recording from your Alesis by plugging the out from the keyboard into the 'in' of the MBox, correct? if that's the case, you are NOT recording MIDI data. remember that MIDI does not record sounds, it just records note messages. and from the looks of your setup, and looking at the MBox specs, you don't have your keyboard hooked up via MIDI (i.e. the MIDI out on your QS goes into the MIDI in of your computer).
in order to record MIDI, you'll have to get a MIDI interface. i'm using a
midiman USB midisport 2x2 . it's a pretty good box, 2 in's, 2 outs, good X drivers, you can find it for like $60. i was kinda surprised that the Mbox doesn't have MIDI, thought it did.
anyway, so to record MIDI from your keyboard, you connect the MIDI out from the keyboard to the MIDI in of the computer, and while your at it, you can do the out from the computer to the MIDI in of your keyboard. now, record like you were doing, but instead, create and record to a MIDI track. in the track, you won't see a soundwave being recorded, but instead little squares or rectangles in a grid, which correspond to the notes which your pressed on your keyboard. now, when you play back that track, the MIDI data that you recorded is sent from the out of the computer to the in of your keyboard, and you should hear exactly what you played from the keyboard's audio outs.
but since this is MIDI data, and not actual audio, you can now go into the track, and change the patch or voice of the keyboard to anything you want. and you can quantize the MIDI data, fix notes that are off, etc. you are not manipulating audio, but are manipulating the messages that will control audio.
i think if you get a MIDI USB interface with your QS connected, and set it up using Audio MIDI setup found in Apps-->Utilities, you should be good to go.
tr