Take the difficulty down to where I had it. Trust me, the game will be hard enough as it is. Looking back on my trial game, I had at one stage 59% of the galaxy under my direct control. That included two high PQ planets that the Torians had surrendered to me. I did make some mistakes in that game which I do not intend to make again, however, the starting conditions were skewed so badly in my favour that I almost thought I was cheating. Controling over half the galaxy after initial expansion was not enough to sustain me. Don't get too ambitious with the difficulty just yet. Remember that Maso players started playing SGs on lower difficulty levels.
The real reason that AW in Galciv is so hard is the double hit on income. The major hit on income is the loss of trade. The second major hit on income is the lack of population that comes from both pop lost to transports, and due to the fact that you will not get all the trade goods/moral buildings that you normally get. Trading with minors may help a tiny bit, but to keep up militarily you will have to research the ship techs and power-up techs anyway, which gives you less tech trade options. The higher the difficulty, the deeper and faster the downward spiral goes. I kept up and did OK until the AI got their first Death Knights. Once they got them into my ranks, I had no hope. There are no lucky rolls in Galciv.