What kills me if is that I know if I was there, I would make the thing do what Eddie wants (its easily done with a multi-out card) and MME would have absolutely NO affect on the situation.

Simplify it in your head. You want to send 16 outs to mixer (enable 16 outputs in RB output driver section)

Route each track to which of the 16 outs you want (using right-click on track and select 'port')

Play song and make sure it plays to mixer.

Route wires from mixer (your mix) back to input 1/2 on Motu unit.
Enable these inputs in drivers section (and only these inputs so they are default)

Hit record; RB should play the song out those 8 outs to Mixer. Mixer sends it back to Motu input (which records it) onto a new blank track.
If you hear the original tracks in the recording, it is an issue with the MOTU unit routing the outs back to the in.
The (often) complex missing part is the device mixer; you have to make sure all those tracks going thru the Motu on their way out are not getting routed back into the input side accidently. This happens when 'monitor mix' or similar is used in a soundcard mixer applet.
If you hear your new mix in the recorded track, the routing is correct.

I'm sure you can get the MME drivers set up again. The access violations are likely due to changes made to settings. If MME works, it'll work for this application. If you need ASIO to hear those outputs, then you'll have to go that route.

I do not work here, but the benefits are still awesome
Make your sound your own!