Ironwang, mostly entirely agree. The MP exploits need to be addressed.
I think check boxes for rules would be great. No unwanted coup/boost, no non focus War before 1937-9, major must keep ideology, all would be candidates.
I think you are on the money with the Axis majors needing an overhaul, aka they need to be brought down to earth with malus and gating because the generic is too strong.
I disagree on principle with rules limiting division design. I want 15 art 5 inf to be buildable, but I want it to be so bad, that no one would use it. In the same way with fleet you have de facto limits on # of CVs, and there are ideal ratios to Capital/CA/Screens.
Mechanics of the template components should drive division design, not arbitrary division width to equipment used ratio mechanics (IE one line art/aa/at per 10 width).
If people want Tanks in their infantry divisions; there should be a counter to that strat.
I think the big thing is to not let one division, fleet, airwing become THE division, fleet or airwing. The eternal Rock, Paper, Scissors meta of RTS needs to play a role here.
If people start putting tanks in inf divisions, then AT guns should be cheap enough to produce enough of (with foresight) to stall out a tank push...over time. If AT guns become the thing, then soft divisions should become popular, then divisions with high SA should work to counter those, which leads us back to tanks in inf divisions. Thats how it should works in base terms.
I am not certain if it isn't happening because the balance isn't there, or if there is a general unwillingness by the MP community to iterate through strats to counter things like space marines and develop a mutating meta. Instead it seems like people would rather know what the definitive "best" division and strat is, then play that division and ban anything that deviates (All that said, it is disappointing land combat works in a way that makes 1x 40 width > 2x 20 width).
Total Aside:
Also, I think in a "Historical" MP game, Germany should be forced to take Rhineland first (Especially if he is a good player). World tension can be gamed too well by good players (and if you are playing MP with people on Axis majors who dont know how to gate tension properly then it is likely a Allies/Commie victory unless they are even worse).