I watched the video, and you do not need to link thrusters to the core. If that was ever necessary, keep in mind that video is old enough that much has changed in the game.
Tip: If something needs to be connected to the core, or weapons computer/ etc. and is not, when you go to fly your ship, or shoot your weapons, they will simply not work. So if you go to fly your ship, try to move your finished ship, and it doesn\'t move, then something is wrong.
Again, you need power blocks placed for your ship to have the power to use the thrusters. But currently, you do NOT need the thrusters connected to the ship core.