Well, that was odd. EDIT: Hey, forgot to upload screenshots, fixed soon. Also forgot to display my defensive set up, if it is of interest to anyone.
So I reattempted this. First, I did some careful raid starship micro to take down the warp gates surrounding my home command. Second, I sent my Stealth Battleships east to Pz-zazz to start softening that up. I was hit with two heavy raids of fighters to Monea in the south. Various fleets and Raid Starships were sent southeast to Esflovian to clear that out for a new chokepoint, one hybrids would have to come through in order to harass us. This took a while as I had to pull back and forth due to the 1000+ patrol waiting one system further out. THe ARS lay forgotten for now, Reprocessors are not worth it, and time is pressing. This time I was a lot more careful about shepherding my fleet ships, riot starships, combat starships, and fleet starships. I hadn't fully rebuilt by the time the CPA was announced, but this time I lost nothing more than 1 Raid Starship MkI, 1 Riot Starship MkI, and 4 Heavy Bomber Starships.
Here's where it got odd... The CPA was announced, but the Defensive Hybrids had not mobilized. I did have around 20 Hybrid Hives next door I actually was able to take out/scare off with minimal casulties, thanks to my Champion (with full shadow charge), 9 Riot Starships, 4 Plasma Siege Starships, and *just* my mk1&2 Fighters, Bombers (1/2 my cap actually) and Frigates. I admit to running out of shadow charge and pulling back before everything was done, but I was quickly able to re-engage.
Here's a map of my system. My three immediate strategic goals are: settle and fortify that chokepoint (this includes clearing the system to the north), initiate the first stage of the Spire Campaign (taking out what warpgates I can and keeping my eye on the rest, and strengthening my military capacity (this most likely means grabbing that ARS but I would have to spend the time hacking it and I'm not comfortable committing my forces to that yet), but may mean grabbing the broken Hive Golem instead if it looks like my economy can support it.
My midrange goals include getting mark 3 scouts and exploring the neighboring clusters significantly, establishing the Spire Outpost, and establishing a foothold in the neighboring clusters. Any decision about settling the Fallen Spire cities is premature at this point. My champion is still quite a ways off from accessing a nebula, let alone my empire being weaned of reliance on its abilities.
edit2: and now the Defensive Hybrids mobilized. After the CPA was freed.