i haven't gotten so far out of the box yet as to use outboard gear - but i'm planning on doing that soon!Would you run the outboard gear (ie. Reverb, compressors, delay units, etc) through the aux channels (i have 4 on my board) in/out of the board? I'd have to, i guess, seeing as how there are no more outs available to run a processor loop through the digi002. Thats one setback, it cuts my in/out for effects in half (from 8 in/outs on the digi).
i don't know too much about the mixer you have, but chances are that each of the channels have inserts, and it's likely that the groups and the master section have inserts as well. the inserts allow you to send the channel's audio out to a piece of outboard gear, and then send it back to the channel, where it continues on its route through the mixer.
if you're not familiar how inserts work, i can give you a more detailed explanation.