[Captain Kwok]

Instead of creating whole new lines of techs for each racial trait - focus on weapons and bonus facilities that match their trait and expect characteristics. For example, an Organic race might need to extract lots of organics, but instead of creating a whole new line of Organics Farms, create racial bonus facilities that greatly increase the output of the basic facilities.

Make normal weapons weaker than any racial trait weapon (i.e. leave them for neutral races etc) and you won't need to restrict them because most of them just won't be worth it unless a racial trait has a particular weakness etc.