[Atraikius]

1) The AI for the demo and the full Version are the same files (as far as I know), the difficulty settings may be a little difficult to understand, they involve the AI use of ministers and only on 'Hard' difficulty settings does the AI use all ministers available (so using lower settings actually limits thier performance, instead of higher levels giving them a boost). The AI Bonus is what gives the AI a small advantage over a human player by giving them extra resource, research and intel points.

The stock AI still is lacking even at Hard difficulty with a bonus, which is where the enhanced AI mods (TDM-modpack) come in. The AI's still tend to be a bit predictable, but are much better in following what they are designed to do (and sometimes the AI creator has been creative enough to make the AI pull some surprises on you occasionally).