Let the agent manage the mines and reffineries. You could apply the strategie to the Empire but you would have to build a transport on one of your shipyards (if you don't yet have a transport in one of your fleets) to start and colonise the outer rim. About ships. I suggest you read the encyclopedia and note which ships have a reasonable power with a rather low cost. Anyway, at the moment when you will really need to have a powerful fleet your researchers will already have discovered improved ships such as: Correlian gunship, Nebulon-B, VSD II, Mon Calamari and so on.