Concerning:
6) On a related note, I didn't check this myself, so can anybody confirm that Logic still doesn't have MainStage's MIDI-input assignments? In MS, you can tell each channel strip what device and MIDI channel to use, just like in every other sane DAW. As a result, it's never been quite feasible to do multitrack MIDI recording.
You can already do this in version 8.
Set the midi channels correctly for your tracks and record enable them.
Set "Auto Demix by channel if multitrack recording" option on in File->Project->settings->Recording
Cheers
Andy