I recently forced myself to persist for a couple of tries with the Arceans, just to see if there was something I could do to make them work. I did eventually do pretty well, but it required some serious adjustments to my starting strategies.
- I decided that the colony rush is really more about production than speed, and in this respect the Arceans are no worse than anyone else. Crank out those colony ships whether they're slow or not. A sensor bonus certainly helps so that you don't waste too many of your precious moves.
-Research those two passive speed bonuses pronto, but don't build any nav centers. They're too expensive until mid-game. Instead, trade with someone else for Ion Drive. Re-design your core ships with dual Ion Drives - gives them an extra move and they only cost 10mp more. This should get your colony ships up to 5 moves a turn, which is as fast or faster than everyone elses at that point.
-Not having recruiting centers sucks. Once more, trade for them. Most civs will let you have that tech for a song.
-Re-roll the game until go get a central-ish starting position, or otherwise have lots of star systems around you. The early speed penalty hurts less if your ships don't have to travel as far.
Hope that gives you some ideas.
