You have some good points, but for a civilian/LE rifle a flash supressor or compensator is just not needed, in fact I have removed them from other of my rifles and have improved accuracy by doing so.
Mags are expensive-I have 6 of them but do not anticipate ever needing any more, they are easy to maintain and I cannot imagine a scenario where I will need massive firepower.
Cleaning from the front end is a pain, but has to be done with many rifles, particularly semi autos, I use a bore protector(or like you a pull through in the field).
Taking down is easy, but does require a tool as you mention.
In any case at the price point (under a grand for the Winchester model, just over for an FN) you just cannot find another semi auto that will provide this kind of accuracy out of the box, the only other rifle that I have owned that would give MOA accuracy out of the box is the Savage bolt gun-and it is really a great buy.
When I was a kid, everyone marveled at MOA accuracy and it was the holy grail to achieve, and could only be done with an "worked on" rifle. Now folks take it for granted, and in a semi auto! Who would have believed it in 1960?
As far as aftermarket stuff, who needs it with an accurate rifle that shoots from a 20 round mag into one inch? I cannot think of a single thing that I would add to mine, although I do covet your light barrel for schleping it around in the field. I suppose for a short light barrel you might want a light hanging on it, but there are rails for that already installed.