I understand your argument regarding the technical benefits of a low bore axis design, John. I just do not agree with your emphasis that it is a major issue. I see it as a minor one that you are overemphasizing and that the SIG Sauer as a package is a very attractive sidearm. While you see a technical "flaw" I am looking at ("feeling") the weapon as a whole. Kinda like pointing out that our LR's use technically obselete Buick engines, use Lucas electrics, leak more than average, etc. While possible true, it isn't the whole picture (i.e. it's more than the sum of it's technical flaws)
I agree much more with your logic that the DA/SA mode of operation makes the SIG (and other pistols that operate this way) as potentially inaccurate in a double-tap scenario. I have practiced firing DA/SA transition and I am not as accurate as SA-only but I am improving. However, for me, the Glock's trigger action feels very much like a DA-only weapon and the long progressive trigger pull is even worse at causing inaccuracy. That's a big reason I do like the P7 is the "squeeze-cocking" brings the trigger to SA mode for enhanced accuracy.
I have also heard for years the story that Hitler would not approve funding for an intermediate-round based "rifle" as well and that's why Haenel in development called it a machine-pistol. This was supposedly based on Hitler's WWI view that a rifle must have a long-range capability or be a trench weapon.
However, the k98 (karabiner mod 98 or shortened Mauser 98) was supposedly a "carbine" so Hitler's alleged bias wasn't against a shorter rifle but rather against a smaller round. My understanding is when he saw the weapon he dubbed it the "assault rifle" due to it's ability to lay down a field of fire when attacking. Furthermore, there have been "assault rifles" that are chambered for the very rounds you mention as "full-power" such as the .308. Certainly the FN FAL, G3 (I can't remember if the original CETME was .308) and the original AR10 stoner design, M14, etc. I think you might even argue that the 7.62x39 was ballistically similiar to the .308 so the AK-47 as well.
I consider a carbine a "rifle" but simply a special purpose rifle. Shoot, if you argue that the M16 isn't a rifle than what's the M4 carbine?