Guess what would IMO be much more realistic for capship AI and would improve some things a lot?
Make the cap ships move so that when they change direction, they begin the turn slowly, then gain angular velocity until they reach their maximum turn rate, then slow down the turn until they point to the direction they want to go.
That would be way more realistic than the way they currently turn. Currently they reach full turn rate immediately from the start of the turn and when they stop the turn they seem to suddenly throw their angular momentum to the same place that inertia in FreeSpace games in general is. It has always buggered me the most in these games.
It is, by the way, one of the reasons why the Colossus behaves like a baseball bat. Even though its CoG is set a bit behing, it wouldn't look so ridiculous if it actually behaved like it actually would. Of course it would need additional programming to make sure that the ship didn't overshoots it's desired direction, which would cause oscillation if the AI would continuously overshoot it's target.
Funny thing is that if a player controls a capital ship, they automatically do behave like this. Which means that it is indeed AI-specific.
The AI would need to consider howe long does it take to get the ship into maximum allowed turn rate. It could, for example, demand a 10 degree turn to accelerate the rotation to maximum. That would mean that the AI should first calculate how much it needs to turn the ship (in degrees), and then define how it should turn the ship to that direction.
If the angle of turn is exactly 20 degrees, the ship would start turning to desired direction, accelerate the turning speed until it reached the halfway and maximum turning speed, and immediately start decreasing the angular velocity so that the ship would in the end point at the desired direction.
If the angle is less than 20 degrees, the ship AI would accelerate the rotation until hitting the half way to the turn, and then slow down the turn for the rest of it.
If the angle is more than 20 degrees, the ship would reach maximum angular velocity, retain it until being 10 degrees from the desired direction and start slowing down the turning in order to avoid overshooting the target vector.
Please tell if this wish is too far-fetched.

Another thing that might make the AI fighters and bombers look like they are controlled by human pilots: Do they ever use anything but pitch and yaw axes? I don't remember them using roll control very excessively.
Also, adding some small, random flight patch changes and corrections when flying from point A to point B would increase the humanity factor in the AI a lot. Some small, random weaving would be more believable than picking a direction and then flying toward the waypoint without even touching the controls.
And of course... Make them avoid collisions better. I think we all know the horrible feeling of pressing C-3-7 and being rammed by all your wingmen. Especially if you're flying at low speed and you turn around...