[Mybe not a Major AI Flaw] AI NEVER EVER uses strategic spells!
I have played quite number of games so far. But NEVER EVER has ANY AI faction used ANY strategic spells on me!
Example: In my current game another faction declared war on me and one of its armies was quite close to one of my cities. My nearest army was not close enough to reach it to defend the city in time, so I tremored the opponent's army and while my own army came closer I seized the opportunity to roast it with pillar of flame. NEVER EVER did ANY of the AIs I fought pull something similar on any of my armies when I invaded its territory.
Also I never saw lower land or raise land being used by an AI faction.
What good are the strategic spells if only I use them?!