Is the bonus given by the Eyes of the Universe moddable? I suppose I could just not build it, but I'm curious to see how the game would play if it was changed from 15 (I think that's where it is now) to 5 or something.
AFAIK, the Eyes of the Universe has two affects: a +15 sensor bonus, and the ability to see all ships in the mini-map. the former can be reduced easily enough, and the latter can be deleted entirely if you'd want.
I don't know how the AI would react to the bonus other than the increased LOS
actually, i remember reading something (by either Brad, Kryo, or something else 'in the know' of the AI) that basically said that the AI needs to be able to see a ship to react to it. so i'd say, yes, the AI would play better if it built EotU.
here's an experiment: set up a small game, get going, build the EotU on some meaningless boarder world, gift the planet to an opponent, and then see if that AI suddenly plays any differently/better. of course, you could also just mod an opponent with a huge sensor bonus. i may try this myself when i get home.