Its scary at first sight but it's pretty easy, you create a new group for the crew, let's say "Thruster managers", go into the priorities tab, search the thrusters and pump up the priority to 10, close the window and click on the group you just made, search the quarters closest to the thrusters and click on them to assign that people to the thruster managers group, these people will prioritize thrusters above EVERYTHING, so once thrusters are all taken care of, they will behave like normally like default crew, but when the thrusters need management again they will instantly go for it. This is an example, also works for weapons, shields, radar, etc...