Hi Errol,
You will find the eQUEST Users list to be a helpful form. http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
I rarely participate in energy-models.com (just a time thing; not judging the site) and I have not seen the training video. I also do not use the "dummy zone" method of modeling DOAS.
I created my own method for modeling DOAS systems. Google "DOAS workaround using plenum spaces" for a description.
See my responses to your questions below. Good luck.
~Bill

William Bishop, PE, BEMP, BEAP, CEM, LEED AP | Pathfinder Engineers & Architects LLP
Senior Energy Engineer
134 South Fitzhugh Street???????????????? Rochester, NY 14608
T: (585) 698-1956 F: (585) 325-6005
bbishop at pathfinder-ea.com?????????? www.pathfinder-ea.com