active verses passive
Without going into a lengthy explanation or opinion I don't really know how to cover all the possiblities. But let me try this and see what other opinions you get.
First of all to do a "pink noise" test you have to have a pink noise signal or generator. Pink noise as I understand it, is a signal covering a given frequency range, in general for audio from 20HZ to 20,000HZ, with all frequencies produced at the same level. This signal is played though a reference amp of known quality and then sent to the speaker to be tested. A reference microphone is placed in front of the speaker at a given distance that is routed through a spectrum analyizer, generally a 1/3 octave spacing, at which time you can tell what kind of performance you are getting from your speaker cabinet. What you hope to achive is a perfectly flat response from your componets through the entire useable frequency range.
This is what you want from either passive or active in my opinion.
What I mean by this is powered or non-powered cabinet.
Personally I would buy the non-powered and would buy the best amp I could afford. I think this is the most practical in the long run. Low frequencies require the most power to reproduce acurately and to have a powered sub-woofer for your bottom end has advantages. The biggest problem with speaker performance comes from building the crossover network for a given set of componets so that you do not have an unwanted coloration of your music (the choice of componets is a factor as well). And that imho is why you want the flat response, so that when you boost or cut you are dealing with your music and not the limitations of your speakers. Which way you achieve this is not important in my opinion. I would think most pro music shops have the components to run a pink noise test, getting them to set it up, well I guess you'll have to ask and find out.
One final thought. When I buy tools anymore I try to buy them for a specific purpose and not a one tool does it all. I think amps are built for a specfic use and speakers can be built for a specfic use, for some reason combining the two does not seem like the best approach for a studio, but that is just my opinion. Subwoofers on the other hand is an "EXCEPTION TO THE RULE" I would make, for reasons I'm not going into right now. Something I think is also important when you do your mix is to consider what the most likely enviroment your music is going to be replayed in and mix accordingly, i.e. a car, boom box, home stero and not to fool yourself with your sound system but again that is just my opinion.
I hope my opinion finds support among most of the members and I really think it should, but I learn something new every day. I hope this helps. Some of the things you mentioned do not jive with my experience, it may just be a matter of terminology.
Keep the faith, Ozlee