galaxy flyer,
There are many more factors in aerodynamic design than just wing loading-- span loading (the flip side of aspect ratio), airfoil, finess ratios, thrust loading, drag, in all its components and installed high lift devices.
I assume by fineness-ratios you mean T/C ratio; by span-loading you mean the ratio of span to chord; and thrust loading you mean T/W ratio?
A number of fighters have greater wing loadings than the DC-10 and perform fine, for their designed mission.
Like the F-105, it performed decently well in regards to sustained agility when flying faster than a bat out of hell at low altitudes when lightly to moderately loaded; at lower speeds it bled off speed way too easily, and at full-loads, even it's high-speed agility fell off.
Yes, under G loads they lose speed, but FAR 25 design is for 2.5 positive G and all of them possess the power to overcome the resultant induced drag.
They can all hold 2.5g without loss of airspeed?
Yes, airliners have undergone proof levels G-loadings, usually they have been associated with a deep nose-low attitude and no amount of G prior to breaking the airplane would result in a stall and "falling out of the sky".
I was largely talking about while in level flight, not in a steep-dive.