There definitely appears to be a lack of early war in BNW

Same here. I was particularly shocked in my last game with the Shoshone when Shaka was my best friend throughout almost the entire game up until ideologies, where he had no choice than to go after me by then. Of course, he lost his campaign, as in 95% of all AI war campaigns. And, we shared borders more than half of the game and we were still friends. And Shaka had a decently big empire.

So, yes, things are way more peaceful in early-game now than in G&K. I mean, it's just a feeling when that happens in one game. But, it's almost a fact when you play 4 Emperor games and you don't see early wars in any of them, and you even see Shaka and Suleiman being nice to you through almost an entire game when you're almost always last in Soldiers numbers.

Something feels definitely wrong. We need more challenge. My theory is that they reduce AI aggressiveness for releases and then "fix" it in the fall patch for hardcore gamers.

I play mostly on Emperor. What are your experiences there and above? Do you need to force a crowded setup (many Civs) to see early wars? Do you also feel that the AI is more keen in declaring to other AIs, than to the human player? Come on, I was last in soldiers in my entire game and everybody liked me. I can't be that good at diplomacy

I agree that the AI is less aggressive than before, but for situations where the AIs don't seem to be declaring on each other, bribing them to war is still about as effective as it was in G&K. I consider myself to be in derelection of duty if I don't manage to institage at least 8- 10 wars over the course of a game--ideally as many as possible before the World Congress comes online. It ensures the AIs hate each other as much as possible. The side benefit is they are less likely to trade with each other, leaving even more stuff for you.

Sometimes I'll use what Civ 4 players called "triangle diplomacy"--pick two civs who like each other and push together in terms of friendship, while provoking everyone else into chaotic wars with each other.

Disable barbarians problem fixed AI spend all their units at barbarians