I am not playing galciv2 that long, but I'm doing quite well: Recently, I changed to suicidal difficulty and that's really hard...but after I almost won a game (just didn't play to the end) with a bit of luck, I now turned to the same settings, but without tech trade this time:

Settings:
Medium galaxy, 9 opponents, everything abundant, tight clusters, normal technology rate, no tech trade.
Race: Drath Legion
Abilities: Racial abilities + 30 economics + 10 morale + 10 trade + 20 social production + 20 soldiering

The no tech trade part was to make the game even harder, so that you do not get these far ahead technologies of the ai relatively cheap in trade given diplomatic superiority.

Game Report:
Micromanagement:
In the start everything has a lot to do with micromanagement (resetting military/social/research distribution every turn) and grabbing as many colonies as you can get. In this game I decided to buy a manufacturing capital in the first or second turn of the game for my homeworld. What I achieved with this was to be able to produce a colony ship every turn by game turn 4 or 5. Buying colony ships is IMO the worse option as producing them in this way. If you have one or more bonus sectors for manufacuring on your homeworld, this strategy will pay off. I had one with 100% on my homeworld and it was enough to get me started with my manufacturing capital. I just played another game and looked a bit closer at it: With a factory on a 300% manufacturing sector and 2 "normal" factories along with the manufacturing capital, I had to use ~60% for military production in order to produce my colony ships every turn. With space militarization and/or planetary improvements it will be less.

Tax Rate/Industrial Capacity:
Tax: 0%
Industrial Capacity: 100%
I set the tax to 0% to be sure to have an approval rating of 100% without doing anything else for it. I generally avoid building morale buildings and still can set a high tax rate later on.
Why 100% approval in the beginning? To get the population of your colonies growing faster. There will be a bigger payoff some turns later when you actually need to collect money.
In this game I needed to set the industrial capacity as low as 50% for some turns.

Early technologies: As lots of my ressources went into the military distribution, I did not do much research in the beginning. In this game, I had warp drive relatively late, maybe game turn 15 so that my colony ships could not profit much from it. Normally I would go for xeno research by game turn 1 or 2 and then switch directly to impulse drive and sensors after that. Maybe I would throw in space militarization in between to get the +10% to military production.

Colonization:
I was able to grab 6 colonies in addition to my homeworld. Not too good a start considering the ai has these tremendous advantages.
After the colony grabbing phase was over (and it's over very fast on a medium map, 9 opponents and their production bonusses...), I had to focus on stabilizing my economy and avoiding wars. With a no tech trade game, it's not that easy to avoid getting pummeled by the ai. The +25% to diplomaxy of the Drath Legion still pays off here. Yet, I think I had to pay a monetary tribute 4 or 5 times in this game. Not a big issue, but a bit annoying in the start when money is lacking. Researching weapon technologies is an annoyance, too, as there are always things that seem to be more important, but after 3 or 4 ais had begun to produce military, I also researched lasers I and II. Lasers because you can fit more of them in a ship and get a higher attack rating in the beginning. I also equipped some cargo hulls with as many lasers as would fit in there to get a higher military rating.

First War:
It was soon clear the drengin and the yor collective would be the major players in this game. The Torians had the third highest military rating when both Drengin and Yor declared war on them. This is when I produced some sensor ships and placed them in Torian territory while simultaneously researching invasion technologies and producing troopers. This time I was careful not to place any transports anywhere near to any ai planet as they tend to declare war very fast then, even if their planets are in your territory. So the best is to design a transport that is fast enough to hop from one planet to the next without any stops.
Without any "warships" that could move more than 2 parsecs, my troopers had to rely on scavenging what the Yor and Drengin left over. I believe I got almost all of the Torian planets.

Abusing the Torians:
As the spoils of war - their technology - was of utmost importance to me, I tried to make peace with them and giving them some planets in addition to that (and securing some gold for me...). Only to invade them again in the same turn. And lo and behold, I really got another technology out of the planet. Needless to say that I milked the Torians in this manner for some more technologies. Skowbo I and II were given back to the Torians at least 4 or 5 times...

So, I found myself circumventing the "no tech trade" game in this way. But it just didn't feel right. Actually, I thought that the developers would have thought of this possible abuse and give each planet only one opportunity to yield a technological gain. But for whatever reasons, there is no such cap.
And what did the Torians and the other races do? After some time the Torians complained that I would only be doing peace just to attack again. They were right, but what did they do? Accept my next proposal for peace with some nifty planet gain for them yet again. It was only after 6 or some such occurences that they didn't agree anymore.
And how did the other races react to that? I would have expected that my relations with them would seriously detoriate after such a policy. But obviously, they did not care what I did to the Torians. Making peace, attacking, making peace, attacking etc. There was no change in the relations to the other races at all. But they could have been (and were) next with this policy.

If there will be a patch 1.3 I would like to see both issues adressed for an (even more) realistic gameplay. Only one opportunity for a technological yield per planet and some serious consequences for abusing a race. I mean, the Torians even detected the attack/peace/attack pattern, but did not care too much in the beginning, falling in to the same scam again, while the other races did not react at all.


How did the game end? The Thalans fell prey to another combined attack of the Drengin and the Yor. Flying to the other end of the galaxies with my transports would certainly have provoked some war, so I didn't scavenge any planets there. The Terrans were in a short war with the Dominion of Korx and I joined in to get some planets again, but they signed a peace treaty and I found myself battling the rest of the Terrans alone. But they have had only 3 planets from the beginning and couldn't even stand a chance against a prolonged attack of my weak fleets. I got some nice phasor technology from one planet and could start now to build a real fleet. I should have invaded their last planet, too, because now the mighty Yor Collective declared war on me, as some race had paid them to do so...
Just as I saw my end coming, despite distracting a good portion of their fleet with a colony ship in the edge of the galaxy map, the Drengin joined into my righteous war against the Yor. There is nothing better than seeing the two most powerful races battle each other.

I even conquered two planets of the Yor, albeit with no technological gain, when the game suddenly crashed. I don't feel like playing from the last save again, although it were merely 10 turns. Somehow invading the poor Torians and Terrans again and again feeled like cheating
It was just like circumventing the no tech trade option.

Any comments/suggestions?