All the changes proposed look pretty sensible to me. I did have a scurrilous thought about the 1:1 rule, however. I've been struggling with a game recently where the Sov is an expert checkerboard defender - late in the 1941 Blitzkrieg I basically got nowhere because he'd constructed and filled with good units a checkerboard of considerable strength (fort 2/3). I had this lovely thought that any hex that was attacked without an adjacent unit or stack (wherever -- just so long as adjacent, not necessarily alongside) would be made to suffer the 1:1 rule (for both sides, not just the Soviets). This would have two useful effects:
1) Soviets could still get the benefit of the 1:1 rule in 1941 attacking the fast-moving panzers which, in almost all cases, tend not to be adjacent to another friendly unit or, if they were, would force the German to be a little more realistic in spreading out units. This situation seems useful - making the Soviets more capable of attacking spearheads, but not the main part of the army.
2) Germans would get some relief from the checkerboard defence - sure, Sovs could do it where necessary but at some penalty.
It makes sense - units defending without any adjacent defending unit would be easier to shift.
I appreciate this might be a major code change, however, so just offer the suggestion as one which balances the benefits of the 1;1 rule and also solves another issue - checkerboard defence.
(note, I never want things to be taken 'out' - just that the tradeoffs for and against the checkerboard are too heavily weighted in its favour).
I still remember cardboard!