I agree with OP completely apart from his critique of the instant upgrades for military units. I think this actually improves the game. CiV was the same, only that it came down to economic power. Loosening the connection between military and economy a bit is a good thing in my opinion, as the economic superpower tends to be the military superpower anyway. This is countered a bit in BE. Together with the lack of barracks etc. the game allows for a much more intuitiv management of one's army.