Well, I'll make an educated guess based on what information I've seen so far:
For traits I'd go Intelligent, Communal and Weak or Sedentary. Communal increases happiness which is a direct increase to every resource produced by every pop of your species, including research, allowing you to build, keep and get more out of more research stations. Weak shouldn't be much of a problem as it looks at first glance, as you can research and equip your troops with damage-increasing attachments to mitigate its malus.
Fanatic Materialist is the obvious first pick, although I'd be interested in, counter-intuitively, taking the Fanatic Spiritualist road, because of the Happiness argument I used above, but I'd need to first actually play the game to know if cybernetic techs are better in this regard compared to psionics. Third Ethos point can be spent on Pacifist(if you want faster pop growth), Collectivist(if you want to lower the chance of starvation and enslave pops working in Minerals and Food; in that case, switch out Weak for Decadent) or Xenophilia(decreases the happiness malus if you want to conquer more worlds, and happiness = production). We'll need to play the game before being able to tell which is better and fine-tune our strategy based on that.
As for government form, I'm interested in first seeing what are the bonuses of the Advanced Government types for Science Directorate(SD) and Despotic Hegemony(DH) to make a better judgement for long-term strategy, but I believe that in general Science Directorate will be more advantageous in all phases of the game. The extra research alternative to pick from is an effective increase of +33% in getting rare techs, with all the goodness that entails. You'll have a more diverse and potentially powerful tech deck, while Despotic Hegemony's bonus of +5% Research Speed pales in comparison to that.
