After reading the 8 pages of comments, I have a few things to say regarding what other people have posted (double post I know, sorry =[).
People have labeled the pirates as being able to wipe out their fleets, what exactly are you doing wrong? I can take 40 pirate ships out with defenses alone, I don't even NEED a support fleet.
I've seen people mentioning that LRMs are too weak, and they die too easily. I'm afraid I have to disagree. The majority of my fleets are composed of LRMs, because they pack such a huge punch and are incredibly cheap to produce. Kol Battleships, LRMs, and Carrier Cruisers + Kodiaks make for a deliciously well balanced killing machine.
About crystal being too hard to get - I agree with that wholeheartedly. I spent over 50k credits on crystals in the latter half of the game at 1-1.5k per 100 and then ran out of them again 10 minutes later.
Also, I disagree with AIs building too much defense. I haven't had a problem with them building up defenses at all (maybe because I've been playing on medium?). My fleets can usually take down their gauss cannons and hangers with minimal losses, I just let my frigates and capital ships deal with the gauss cannons and enemy fleet while the bombers I brought along with my carrier ships make quick work of their hangers. It's all about strategy.
Questions/Suggestions -
Will there be a 'titan' ship class? Maybe a mothership-esque ship that dwarfs capital ships but is immensely expensive to make?

I love the idea.
Please fix the robotic cruiser's sounds. It's immensely annoying when they're all I can hear.
I'm sure this is already being worked on, but the AI needs to be way more aggressive, all they do is fund pirates atm.