When I played the demo the AI: Artificial Intelligence|AI did react to my advances although they did leave many of their troops back to guard their rear, which I thought might have been an overly cautious move. I have the full version now and it is so much better than the demo. The AI is definately a lot "smarter" in Empire than the other Total War games.
The AI is much more aggressive on offense, they may hang back at first to see how you move but then they respond quickly. While defending a seige, if you bomb them with mortars then the AI is smart enough to sally out and destroy your mortars. Over all the AI in Empires is much more advanced and challenging than the other titles.
I would definately recommend it. Even though the demo may be flawed they have corrected many things and are constantly doing updates so the game in total is improving constantly. Hope this helps in your decision.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.