Yes, everything is done with physics. Turn rates are determined by torque application and thrust by linear force application. On the SpaceVehicleEngines component, you'll find settings that determine the amount of force applied to the ship, which is of course then divided by mass to determine acceleration. The Default settings are for when you want to set the exact force in the inspector, and the Power Coefficients section for when you are using a separate powerplant which can, for example, be affected by damage. Note that for the AI, if you want larger ships not to roll too much when turning, you can set the z component of the max rotation angles on the AISpaceFighterControl component: On the AI, everything is also applied in terms of forces and physics.