I would download the pdf rules available for the earlier editions of Axis and Allies and incorporate some of them - the rules have gradually gotten more complex since the '80s.
I often find that much of the Russian fighting power becomes stacked in Belorussia. Btt by building eight tanks each turn, I can easily use the combined forces to crush the Belorussian army, and after that the door to Moscow is blown wide open.
I’m also thinking that an easy way to leave the British Bonus Infantry rule alone while keeping the game balanced would be to connect Iran to India, and allow for amphib assaults of Egypt via the Red Sea. That way Japan actually has the option of entering the theatre without having to go all the way around the freaking world. :-P
Yes, connecting the Red Sea interboard space to Egypt and India to Iran makes sense.