Pretty much all these suggestions sound reasonable to me. One question I have though, is does anyone have access to the statistical winrates that leaders have over a large sample of games? This would be nice to have since I have a couple of slight disagreements with the balance changes but would happily change my mind if I could see some statistics.
For example, I would normally think of Homer as a pretty decent leader. Comparing to Cleopatra who gets a optional rock once per turn, Homer can in some games get some good value here building military as well (make warrior, upgrade to swordsmen, upgrade to swordsmen), and then leave you with an extra happy face (which can combo very nicely with the basilica if its there). I agree with the other age A leaders though, although one comment I saw and kind of agree with is I'd prefer Confucius to pay an extra CA when replaced rather than lose his 1 science. Compare him to Aristotle who can usually get a good 3-4 science before disappearing.
Also, I completely agree with the change to Bach but wonder if Shakespeare is being hyped a bit too much. He is definitely OP if everything goes perfectly according to plan, but other games feels a bit useless. With Bach you just need to have a theatre, but with Shakespeare you have to invest more into having some cards in your hand for a while which is annoying.
Heres a perfect example of where it would be nice to see statistics.
Completely agree with the proposal to change the age 2 tactics. Indeed, drawing fortifications in early age 2 after booming in age 1 is practically an auto win. Same with mobile artillery. Especially if playing with Jan Ziska with 3 cavalry 3 farms, and then drawing mobile artillery, its just game over.
I think the only thing I don't like is the proposal to make green cubes an extra part of the game. This would be a HUGE change to the game. Maybe it would be better to investigate first how the game changes if any of the following lesser changes are made:
1) Max military card draw is extended to 4 per turn.
2)Players can declare before ending turn to take a search draw, which allows them to keep minus 2 cards, but they can draw twice as much as normal. Or maybe keep 1 less card and draw twice as much.. etc.. not sure whats best here. (Kind of similar to some Race for the Galaxy mechanics)
3) Split the military cards and the events into two decks. A player can choose to draw normally from the combination of the two decks. Or they can choose to draw only from one deck at the cost of drawing minus two cards to what they normally should. So if someone has 5 military actions, they can do this and draw 3 military cards if they want. If this was tweaked, it could be a nice way of rewarding lots of military actions without enabling people to draw more than 3 cards per turn.