I think your suggested difficulty settings are too generous.
RE: About the Armours staying the same size in a transport, even though they can carry 3 additional units. It could be justified as rearranging the interior of the Armours without increasing the overall size. If the Armour size increases after the upgrade, it would seem unfair (even though it would be logical) if you could fit fewer onto a Transport - even if they were empty of infantry, so I think it is probably better that you can put more units onto a Transport if you pack your Armours full - it encourages the use of the upgrade, rather than penalizing you for taking it.
