OZUT, you bring up some decent points regarding one's personal utility in growing; I a believer that we should all try to stay under 100 plants as often as possible no matter our legality (my last run of 142 in a 4x4 tray was simply a test to see how dense I could grow a SOG, nothing that I would do on an ongoing basis).
However, I respectfully disagree with your assertion that the OP needs to "simplify" to get what he's after - based on his posts and his setup, he seems to have an "okay" understanding of growing and is not a pure noob, IMO - he's looking for improvements to get him past a certain hurdle, not to simplify even more and understand how a plant ticks (again, just my take on things).
Couldn't agree more on the quality vs. quantity debate, and I touched on this in another thread - 3 600s would be "plenty" of light for most people, but I try to grow the dankest bud I can, which is more light - there's always going to be a tradeoff between quality and efficiency - technically 3 600s would be more efficient, but I'm not sure they'd give me the quality I desired, so I went with 4.
Regarding soil vs. hydro, it's my firm belief that a well setup hydro system is exponentially less work - I can leave my plants for 10 days at a time and return home to find them doing their thing - you can't do that in soil unless you've got MASSIVELY oversized pots, which are inefficient in their own right.
Agreed that trying to take everyone's advice is certainly a losing matter, but I don't think having options to contemplate and research is ever really a bad thing - the OP can see what sounds good for him and then do some more research/testing to see how it fits his setup.
Regarding the CO2, wasn't recommending that to keep his room at 1500PPMs constantly (which is certainly complicated and requires a fairly large outlay for the intial equipment and setup), was more of a quick fix for his ventilation issues to make sure the plants always have at least 300PPMs available to them when lights are on.