DO NOT I repeat, DO NOT use the analyzer on on a driverack. Those yield worse results more often than not. Read up on prosoundweb.com and you'll see the guys that install systems for a living and tour the world's opinions on the driverack's RTA function. Also the unit is going to try and fix things that an EQ will never fix such as PA placement and physical problems such as a wall. Moving a cabinet an inch and hanging a thick curtain to absorb reflectionsis better in the long run.
First off what is it comparing what the mic picks up to? You need a dual FFT measurement system that includes input delay on the microphone, can do a transfer function, can analyze phase response, etc to do the pink noise thing correctly. Some copy of of SMAART would be a good choice. (5.4 is stealable hint hint) Hell, I can supply a mic and use my laptop if that is what somebody wants to do, just pay for my gas to get to there and back.
The biggest problem I see with PAs in venues is the lack of proper coverage, everybody points the cabs at the back wall and forgets that there is a crowd in front of the stage. In the room pictured a monitor wedge on 'stage' pointed at the crowd with just the vocals mixed off an aux from FOH in it would work wonders.
Just my .02
Yea, I have no idea how to run a Drive Rack. Denver Orrender runs our PA for us when he is in town... which has been at all of our shows. He works for TK Thomas' production company out in Wilmington, NC. The PA belongs to Jeff Flowers of Volcano Audio productions. It's easily the best sounding PA we've ever used. It has Drive Rack PA units in the rack, but no analyzer mics, so I'm not sure how they're setting the EQ's.