Minor races are often more valuable as trading partners (sell them tech and grab the few things they have that you don't-not to mention the economic and research treaties, as a minor will let you buy an economic treaty off of them in the first 2-3 years when buying it from a major is prohibitively expensive: in most cases the majors will charge anywhere from 35k to 65k BC) than their class 15 world is to you, except in small and tiny maps, and even then rushing to invasion is questionable.
In addition, in TA 1.95 or TA 1.96, the minor races got a significant upgrade and now actually build and utilize a military. This is relevant in case you find yourself at war with someone and, ideally, you are friendly with minor races of your same ethical alignment. It helps if you gift/sell them weapons tech as well, but it's not strictly necessary. Do note if you can manage to get an alliance with a race (any race, minor or major), they value things that you trade them far more-or maybe it's they value their side far less. Either way, it works out the same: you get more for your money.
Ontopic: If you're wanting to play Masochistic up to Suicidal, choose Technologists and the 20% research bonus with your customization points. You're free to do whatever else you like with the rest of them, but a point in morale for 10% is always a good bet. Additionally, research planetary improvements as soon as is humanly (or Drenginly, whatever the case may be) possible. A rush to Nano Recorders off of sensors 3 is also in order, if you can manage it. As you need sensors 1 to get survey ships up and running, this shouldn't take you off your optimal route too much. Further, if you're playing the Torian tech tree, you'll want to run the blue tree right after planetary improvements (the prerequisites for tech victory) for even more +research. You can pick up a total of +45% research in this tree, but not all of it is worthwhile. However, the first +25% or +30% is relatively cheap.
So why are you focusing on research so much? Well, for one, you need to get things researched, and the AI has massive bonuses (Maso through Suicidal) that most would say you can't hope to compete with (and most of the time they're right). However, on Painful through Suicidal (and particularly beginning with Maso and up), there is a hidden bonus conferred on the player to research, when they have a research bonus. Whether it is selected before the game, from government, researched, mined via starbases, or a trade good, it still counts. I seem to have lost my table showing the values for the different difficulties, but I remember Suicidal as being a 2.64. That is, if you have a +40% bonus (20% customization and 20% technologists), your research production will have a bonus of +105.6%. This means rather than having 140 research from 100 research production you will have 205 (the .6 is truncated), which is approximately a 47% increase.
Additional note: If you like, you can just use diplomacy and tech whore around, rather than actually researching things yourself, but the focus listed above might help you get that far faster.
On the higher difficulty levels, you need, need, need, at least one colony ship per turn-preferably from your homeworld, as it's the only thing that will have sufficient population to actually man them. While a number of players can get by averaging one every two turns, and some of them only have one per three (at least on the homeworld), it's a good rule to live by.
Note: Ignore this if playing a tiny or small map. It is, however, perfectly relevant on medium and larger.
If you haven't tried lease buying yet, experiment with it-but only on your homeworld and only to get yourself the building capacity you need.