To be fair, whether or not an SMG beats an SG sometimes depends upon the attachments and perks. Would it be fair for an SG with no attachments to ADS faster than an SMG with Grip? I don't think it would be. So things like that have to be taken into consideration.
That said, abelthywicked, I agree with everything else you said. In fact, I've posted at length making the same arguments. One thing I would add, though, is that when it comes to "balance" with weapons, what the community never wants to talk about is the fact that certain weapon classes are (or should be) better for certain maps and not so good for other maps.
I would say you are mostly right about the attachments to the smgs, I myself in MW2 have taken out snipers by tapping the trigger on a silenced ump 45, but the point i am trying to make is that with attachments or not, at a hundred feet or more they should have less effectiveness, more bullet spread, or less damage, I mean look at the mp7 on modern warfare 3, when a newbie can easily pick up the mp7 and accurately hit me from across the map, is rather ridiculous, r in BO2 when a scorpion or the mp7 can spray a tight cone of about 2 feet in diameter with the occasional outlying at 100+ feet is also ridiculous.
On another note I completely agree with you about people not complaining about map variants and gun usefulness. For example, why have maps been continually configured and tailored to runners and gunners, and bullet tracking and hit boxes specialized for the spray and pray/ fire rate of smgs, I mean I do find there should be maps with various playstyles in mind, but there should also be playstyle specific or orientated for a particular set(s) of guns. Maps like rust, dome fr runners, maps like afgan wastland, for snipers, terminal and mission for a variety of snipers, runners,lmgs, assault rifles, favela and bootleg, which are mildly hard to snipe on, I mean a good variety but without a way to obviously beat a playstyle, like sniper veiwpints with like 4 ways it, or a hallway with not enough escapes for a runner to get off the beaten to reload or cal in killstreaks, seriously the need to make maps like back in mw2, like sub base, favela, karachi, quarry, maps that had flw and functionality for a variety of play styles