Bognor, thank you for the suggestions. I'll try applying them. Here's my comments in order,
Put two or three Space Docks with engineer support near the wormhole and churn out Fighters and Space Planes to immediately replace any that are destroyed. They're cheap enough that you can do this. Select the Docks, hold "V", and right-click near the wormhole to have all ships built immediately move to battle.
Hmm... I had never considered this as a strategy. I tend to keep construction efforts in my home planet exclusively so I can pump ships out in a centralized manner. This will likely be expensive, but I'll see if it helps out any.
Use Gravity Turrets to increase the time your dps-dealing turrets have to shoot the Railclusters before the Railclusters can return fire.
I have yet to get a handle on using gravity turrets. It seems that, unless I place the turrets right at the point where the burst of ships happens, they don't do much good for me. As I prefer to defend near my "exit wormhole" (the one that would lead to a planet I'm guarding with this mil base), that's not terribly effective. Still, I can always experiment.
Augment your defenses with mines - they're extremely cheap - and Lightning Turrets - they're very powerful.
I'm still getting a feeling for how to use these effectively. Do you have any links on tips for how to pick where to put them? Is it just "ctrl+click+pray"?
You haven't told us whether you have spirecraft enabled, but Spirecraft Siege Towers should make decent counters.
I don't know what would be necessary to produce those. Is that special ship type I would get at map start?
Strike the heart of your problem by neutering the planet that's producing the border aggression. If its defenses seem too tough, consider taking out guard posts one by one by putting whichever fleet ships get a bonus against a target guard post in transports, moving the transports right up to the guard post, scrapping the transports to immediately unload their contents, then just whaling on the guard post until it goes down.
I have actually just started learning to use this trick in this round of games. Still getting better at it, but my neutering efforts are improving. (I will make Bob Barker proud)
The case in this thread is the worst I've heard about them, but it's not the only feedback I've received that they're OP (in both human and AI hands).
Holy crap, admin comments. I've... never seen that in a game I've played before >.>
I'm a little nervous about being noticed and adding (even slightly) to a consensus for a design decisions, as I know I'm not very good and I could just be stupidly noobish about this. What I will say, though, is that the x20 shots they get feels overpowered when I'm on the receiving end of it. If the ship was more of a glass cannon, I'd cringe but know that the AI isn't going to stockpile them. But as it is, these ships fly in and amidst the chaos of the fight, steadily eat away at every single one of my defenses on the map. And as my turrets fall, the damage gets more and more concentrated so that the effect cascades. My defenses are never going to be very large in number, so my only hope is to very quickly concentrate fire with my lasers and any fighters nearby and pray the AI didn't bring enough to target everything in the first volley.
Actually, as I type that, I realize that I kinda strongly feel they should have a massive damage reduction against turrets (like, 0.01 multiplier). It seems their design is to total the light craft on the map... should they also be overwhelming defensive structures? I dunno... totally don't know enough theorycraft to justify that idea, it just feels like a step in the right direction.
Thanks to all for the comments, though. I'll keep struggling along and see if I can do a video recording of when I get those "wtf" moments. It always makes more sense when there's something to point to