Let me start by saying I don't want to discourage you from trying. I think it would be great to get an improved AI that would work on random map.
You are right. The AI is not very good. I spent a long time trying to make it better, but the problem is that it is completely predictable. You pretty much tell the computer how many constitute an attack force, and they will always hit you with that number. They will never forward build. They cannot utilize terrain to their advantage.
That said, you can make some good AIs for scenarios because you can terraform to the AI/PER or tweak the files to make it appear that it is intelligently developing its civ.
I guess what I am saying is that I don't believe you can tweak the files to make RM exciting, though the Rasher has tried. Or at least, he bundled AIs so that there will be something different in your RM maps. It is very difficult to make it switch priorities, i.e., killing off its Tool units so that it can make Iron units, or deleting fishing boats in a fished out lake to free up spots for worthwhile units. I made some headway towards giving it a boom strat, but it cannot see that you are planning to tool rush, so it just dies miserably, since there is no way to tell the AI to change stategies if one is foiled.
Similarly, you can script a good tool rush, but since it does not forward build, the rush comes from his town, so it hits a couple minutes late. And, of course, since you scripted it, you know exactly what he is going to do.
Let me know if you are successful in substantially improving the AI of the civs.
Keep your stick on the ice.