I like all the races but their racial traits (with a few exceptions) do not seem to fit their history as well as how they should play in the game
True, the races do seem to be sort of generic without a whole lot of variation in their character. There is some, but not a lot. TA should address that with more differences from one race to the next.
One of the other aspects of the game that tends to frustrate me is the fact that it seems like their is no reward in expanding (other than to deny your opponent resources) as colonizing can quickly lead you into economic ruin.
Economy is tough in this game. You can easily lose in the first couple game years just by overextending your expansion. Planets and infrustructure can bankrupt you which may seem counterintuitive, but it does work out if you can hang in there. Once population levels get up there and economy improvements are made, those planets do start making money and if you build them right, a lot of money.
I also really dislike the technology tree with its multiple research project that you must get through before you can actually start doing meaningful research
It does take a while to get to the real useful techs, but I think it needs to be that way. There wouldn't be much point to reasearch if you could get the best stuff very early in the game. Also, when playing in larger galaxies with more habitables, you can build quite a research powerhouse and blow through these boring techs pretty quick, especially if you set the research rate to "very fast" in the game setup.
I think you're finding the early game most frustrating and I can totally understand that, it's hard. However, the reward comes later in the game when you have some real economic, production, and research horsepower. Early game is just something you have to get through to get to the good stuff. Once you get over that economic hump, you can concentrate on what's fun, that is, building warships and kicking some alien butt.