Hehe! Glad some of you
'aerodynamicists
' are not designing the next generation of aircraft
I think the main effect is simply this: Camber and therefore flaps produce a distinct increase in -ve PM on the 2D wing section. Separate the flap-flow and the -PM will reduce, hey ho a +ve (nose-up) change in PM.
(3D effects will alter this, especially on a swept wing )
Positioning of the wing Vs the CG is a static margin issue. The CG of a DC-10, MD 10/11 3 engine style aircraft is further aft than it may seem, hence the wing position 'looks' further aft than a twin. It is not though, necessarily further aft in stability terms. The static margin increases with aft movement of the wing, not forward. However, associated with this, is an increased trim-drag.
If the MD-11 has relaxed stability, this implies the wing Vs CG is further
forward aerodynamically, than otherwise it would be for a given tail volume (moment-arm * area)