The AI attacks my constructor frigates pretty consistently. Pirate raids in particular pretty much always kill off any constructors at the planet before they can erect a meaningful defense. They might get 1 or 2 turrets up before they're gone. This might just be the pirate flak passively targeting them with weapon banks that aren't aimed at its primary target, though. I haven't tried ordering the construction of structures far away from the pirates and the other structures in the well, which would reveal whether or not the pirates are actually focusing the constructors.
Not in my experience. It's possible that the flak guns hit them if you build stuff under the pirates' nose, but if you move them away and have other stuff to keep the pirates occupied, trade ships in particular, the constructors never see any attention. I have a pair of test save games in which I've built 14 turrets while the pirates (one of those giant raids, threat level high, I think) were in the system. Constructors never got attacked. The system had one trade port.
From what I've seen the AI will also move its planet bombers out of range of turrets if possible, though it rarely builds them in large enough numbers for this to matter (i.e. you have plenty of time to build a hangar w/ fighters or a few frigates to kill them).
Yes and no, but off topic so I won't elaborate here other than to say that it moves them about 90 degrees (from the planet's perspective) relative to their initial attack position, so it only works on large planets, but always fails on asteroids, which what the single-colony-ship expansion is predicated on.
Anyways I don't see what's wrong with the AI spamming turrets and starbases. If its fleet is outmatched it will not bother to defend planets with it, which makes sense since it cannot attempt to out-micro a human opponent. In this situation where there are not cap ships and other big ticket units for the repair platforms to focus, a blanket of turrets and a starbase is probably the most annoying static defense for you to go against. Certainly annoying for me at least, even if I can bomb the planet down outside the range of its defense, I still have to clear out most if not all of this rubbish before I can build extractors on the planet, which takes valuable time from my invasion force.
You're assuming that he manages to build the SB, which most of the time if fails to do, the constructor dying to 6-10 LFs in a mater of seconds. IF at least it hit the deploy the moment the SB constructor comes under fire, it might stand a chance of getting something for its credits. But the AI always seem to preplan where he wants to build the SB when the SB constructor is built and it seems it never deviates from that. You just need to intercept/chase it with LFs from the factory or when it enters the grav well. I have yet to see an AI manage to build a SB I wasn't willing to let it build. (Sometimes it's useful to let it waste credits on an irrelevant SB, e.g. one not in your path to his homeworld, as the AI is quite fond of SB upgrades and those cost a lot.)
