Awesome video, loving the content my brother very informative. These videos are super important as it gives the buyers an indication of where the price point of the car should be, also makes the seller abit more nervous that you know what you looking for and hopefully to open and honest with you
6:26 195-50-15 is not actually the correct stock tire size for the MkIII VR6. It should be 205-50-15 and if you want to go to a 16" wheel, then it's 205-45-16. Pretty sure your gearing and speedo will be off by a bit with those tires.
You must trigger the pump and then clamp the pipes from the pump and see if it kicks off. Otherwise it can be the pump. If it kicks off then you need to check for leaks in the system. I usually open the rubber by the door hinge and pinch the individual pipes. Its a job and can also be faulty locks aswell. Good luck