- Added to these problems, AI does not try invasions of my homeland as usually did in previous ages (which was very interesting and challenging), only attacks sometimes with ships but stupidly, it seems to be like paralized.
I've noticed this in my most recent game with 1.75a (I can't install patch b until I finish this game!). The second large empire on my starting continent was running close to me in score and diplomatic relations were very good. Then he went secular and we each got some vassals that the other didn't like, so he decided to use his huge military advantage to destroy my vassals and, in doing so, declare war on me. The scoreboard in the corner showed a 0.4 strength ratio, so he definitely had the upper hand!
He sent one stack of units toward a city that was garrisoned by a handful of more advanced units. The arquebusiers annihilated his stack of units in two turns and then he never sent another. He had some ships bombarding my coastal cities to lower their defenses, but he never sent units to follow up. Bombard, bombard, bombard, bombard, bombard... I let it go for about 60 turns before I finally made peace with him, just to see what would happen.
He's since declared war twice more and done the same thing, only without the initial stack of units. All he does is bombard my cities with ships. It's very silly.