A minor point on your minor point....
the NG forward section removed the drooped cuff that was placed on the Classic wing profile of the original section. The weight increase of the Classic over the 200 resulted in a need for higher Cl/aoa, gained by the cuff. The NG extended the wing span, removed the cuff, and added a re-profiling of the aft section of the mid and inboard wing providing mild aft loading. The ailerons were increased in span, and reduced in chord which permitted removal of the outboard upper surface VGs, the shockwave remains clear of the hinge line at high speed. Flap system was simplified, and track design removed the residual tracks that the Classic carried over from the JT8 aft nacelle. The thrust gate design of the Classic flap was cleaned up, giving an improvement in flap effect, while mainly avoiding impingement on the flap and associated fatigue issues.
The Classic ran out of goodness around .745 but could be pushed higher if needed at considerable fuel burn. The NG for the same weight is running .785-.795 on lower fuel burns than the classic. To run a Classic at .79 takes a lot of extra gas... and while well within the operating boundary is associated with noticeable buffet from the aileron/shock separation. The NG has relatively high approach speeds, which is a tradeoff of the simplification of the flaps. Randolph's paper on high lift devices covers the tradeoffs well.
The Classic EFIS functioned, but the PFD/ND/EIS is supportable and upgradeable on the NG, the Classic being difficult to upgrade piecemeal. The Classic handles better IMHO, but the NG is a more effective transport aircraft,
As far as the fuselage goes, the double bubble profile precludes underfloor LD3 loading, Airbus picks up freight opportunities from any 737 operators.
And If I recall correctly re an interesting offsite conversation in the late 90's- after the time of the MDC buyout and salting the aero group with a few MDC types, there was a major push to incorporate the inboard trailing edge wedge supposedly used on the MD-11 to attempt to meet DC-11 range guarantees. About that time Aviationpartners suggested an early version of winglets and was met with bucu skeptisim- but eventually some test fights were done on a BBJ under the guise of making the BBJ at least look different than the old 737 ( executives like the deluxe hubcaps to show their importance ) provided the winglets did not cause problems. The test results compared to the 'wedge' showed a definite improvement such that ( as I recall ) a german airline ordered a few that way, and the fuel savings on relatively short flights along with takeoff performance was significant.. And the rest is history