energy weapons will say any but seekers. As a result it fires at anything but missiles. This is a bit confusing as I know they can shoot at fighters, though not with the bonus dedicated PD gets.
What's confusing about that? Fighters aren't seekers, and seekers aren't fighters. Therefore "anything but seekers" includes fighters.
I think the reason why it stayed around and waited to get killed is because of the default strategies. It couldn't complete it's primary strategy, so it went to the secondary strategy which was probally point blank. Not sure, but having the secondary strategy be "don't get hurt" might work well with missile ships.