Cities increase science regardless if you annex or not. It is culture that is not increased by puppets. (same as base game)
I cannot guarantee good spy times everywhere. It depends on the city bpt as well as spy levels and buildings.
Yes antiaircraft has always been at balistics but the key difference is that it does not require flight. Makes getting AA a bit faster. Getting Triplane takes longer due to needing biology.
I just finished the map with a science victory on turn 248 (with the official version 6). I think I was a bit lucky not having too much trouble after T150 or so once my continents was clearly in my control while the other one had Rome and Russia at a stalemate.
Catherine was the furthest in the tech tree, starting to nuke Rome around T230.
Not a perfect game due to me not really knowing what victory I should go for.
I used the following policies :
Piety Opener, Liberty Opener, Organized Religion, Republic, Mandate of heaven, Meritocracy, Representation (waited for a natural GA first), Theocracy, Religious Fervor, Reformation (Jesuit)
I then spent 4 policies into honor but that was stupid since I didn't really use it that much and played peacefully after the midgame. Should have went Commerce or Exploration instead.
Later on I went Freedom and Rationalism.
I used Elephants and a few Triremes to take out Harald then later on used Musketmen to take out the Celts. I also had to defend against Morocco but that was easy.
I also let Russia pass World Ideology Order like an idiot and had to deal with -73 happiness at the end lol. My gold management was also bad at the end losing 8 turns while waiting for the gold.
Peak science was in the 2900
Note :
Jesuit education was simply too good and will get a 33% nerf in the next version. But also the AI let me take both Pagoda and Mosques so the faith was through the roof.