I finished the campaign (I won in 9/43) using 5.4 of your mod as the Axis on Normal and have the following thoughts. I went the historical path as the Axis except I did not invade Russia in 1941 and wanted to invade England instead.
I love the mod and still think Fury should work with you on WaW 2 using your work as this is exactly what I wanted WaW to be when I bought it. So thank you very much for all your hard work on this effort.
Weather - The weather changed between the Axis and Allied turns. It really bothered me to start with, but since each turn is 10 days, that could easily happen in RL. Plus over time it will even out so I kind of like it now
MMPs - This needs to be reworked somehow. This is tied to research costs since research is so slow due to the extended timeline that the 'extra' MMPs that went to research can now go to building more 'stuff' instead. While this does make all sides somewhat stronger, it really does not balance out well for the Allies.
As an example, Germany alone was making over 900 MMPs in April '41 and had 139 land units while England was only making around 700 and had 98 land units. The UKs units were spread out over the world while Germany's were more concentrated. The same was true for sea and air as well. I did not start seriously raiding convoy routes until May '41 which made the difference in MMps even worse as convoy income went from around 300 to 100. Waiting for lv 1 subs makes a difference lol.
This is a hard thing to balance over the long timeframe of the game, but I would suggest a 25% reduction across the board in MMP income. As I never really felt a MMP 'pinch' as Germany after France fell. I had no problem putting 5 chits into Russia for a 750 MMP cost to keep them pacified until I took care of England.
US - I know the US AI in the Pacific was not active. The US AI did do a good job in the convoy wars. Once the UK fell though, they were totally MIA. No ships, nothing. They did invade a minor African nation on the West coast, do not recall which one. They did help out a little bit when Japan invaded India with a few US ships but that was it.
Oddities - After England fell, SA declared war by itself on Madagascar. The rest of VF stayed at peace. Madagascar joined the Axis at that point. The SA AI did a good job of invading but neglected to bring over a HQ so they were not able to capture the island. It did take a while to repeal the invasion.
I hope these notes help you. I have saved games at various points if you need them. Just let me know.