Actually, the human brain is far more complex than any form of artificial intelligence we have today, the brain is far more complex and more efficient than a PC, but seriously take everyones contribution and try to add it into your article and it ill get better, just saying not for newbs will not work around here as in this forum this is where most newbs will go to look up strategies, enough of this online newb bashing.
anyway on topic, remember that a lot of things in civ 3 in all ersions rely on the random number generator, and so will never be absolutely set in stone, you make a good point about forts, but they can take too long to build unless you put them up in advance, if you use them, try to put good defence units in them.
Try to bait the ai as you have suggested into attacking units, or as I have read in HOF games, and Always War games, you can leave one city undefended with units around guarding it, and wait for the AI to try and take it, obviously this will rely on artillery, strong units, or if not possible, large numbers of units, and a little luck. (not for the faint hearted)
Use Armies whenever possible, it is possible to get a great leader on defence, and the AI apparently isn't too hot on attacking them unless it knows it can win.
Another factor you have overlooked is government form, wars are best fought in totalitarian governments, like despotism, monarchy, communism etc, and harder to do though not completely impossible in representative governments, (democracy, repblicetc), try to avoid switching at a time when you are weak as all production in cities are shut down. (religious civs can help here)
other factors, prescence of city walls/civil defence, radar towers, lay of the land, and prescence of barracks in cities.
Hope this helps.
SK.
EDIT: Credit where its due, thanks for taking the time to write down and share your thoughts, I just get a little touchy about newb - bashing as its all over battlenet, which puts me off trying to get better at one of my favourite games (warcraft 3) and there is always some cocky little 14 year old who likes to bully others.