Should've read this first.I went in for my second planet, but like I noob I destroyed the AI's Orbital Command Station first, causing the AI progress to sky rocket.Now my main fleet is having to deal heavy AI reinforcements, and now larger raids are moving in fast on my home planet.My main fleet 2 jumps away from home, and I don't have the economy to build a decent defense.I'm doomed.
Best way to keep home base semi secure (at least long enough for reinforcements to arrive if needed) is to pop down a few clusters of tractor beam turrets, then some weapon turrets. I secure wormholes with clusters of 5 tractor beam turrets, clusters of MLRS and Basic Turrets, then I put a few clusters of snipers scattered about (to put clusters of 5 hold Control while placing, combined with shift means you can rapidly place 5 cluster groups quickly).
If you are low on resources then look into mass producing some low requirement ships or turrets (Laser Turrets are very low requirement I believe), and recall either your whole fleet or a good chunk of it to put in Free Roaming Defender mode at home base - plop them in the middle of the system (or the nearest 'mid' point for any incursion wormholes) and you should be good.
AI Progress of 50+ isn't bad, it will go much higher pretty quick - you need to colonize worlds to keep resources coming in, and colonizing worlds means a jump of at least 20 progress (destroying gate and command station) if not more (SF Base, train station, etc).