On the money front, the game is designed so that while your empire is within its "home" region the economy does well, but the further you expand outside of your "home" region the slower your economy gets. Taking Rome as an example, as long as your empire is limited to the peninsula (and the peloponese) your economy will do well, but as start expanding into gaul, spain, central europe, and africa, mid-east to a lesser degree your economy will start slowing down, and money starts to become very tight, and if you try to expand into the steeps your economy pays a heavy price.

To make the game more of a challenge, do not attack anybody for the first 20 years or so as this gives the AI a chance to build up.