Topic: need clarification

My band has added a player and I've needed to add a 5th head phone mix- using a Aphex D/A on the output of ADAT 1 that puts my additional outputs (also for sub mixes) on 13 through 20 (correct so far?). so I'm taking paired outputs into the insert on my headphone amp (which are set to a mono out... so panning on the RME are all set to the middle)

The routed outputs on my DAW (DP 7.2) are independent of the submix outputs, and as I use SPDIF as my main outs for monitors, Analog 1/2 could be used in the DAW as independent outputs from say an aux bus, or should I not use outputs 1/2 in the DAW?

I'm using mono aux outs assigned to analog outs to use as "more me" for the sub-mixes.

Also, what's the trick to "un-linking" faders (paired or otherwise) so I can adjust independently?

hope I've explained myself properly!

and thank you!