Try placing some radial decouplers with canards on the cube (so you can decouple them off when you're in space) and some tail fins on those tanks. That'll help you keep nice and straight during launches.
Okay, so this isn't a space station, but it's too cool not to share This is my habitation station, named after Daenerys Targaryen's dragon, Viserion. The tail was a horrible pain in the rear to bring up.