Hi, I have added some pics of the fuselage and vertical stabiliser. The gap is actually green paint as you can see there is no gap further up the fuselage. The stabiliser looks fine and central, in the video the weight of the plane makes it lean to the left so I have balanced it in the picture.
You could power up the motor and set them as you want also. I test both motors before installing them. Very well noticed though with regard to the instructions.
Definitely do not use any drill as they are fiber optics and you will damage them. Connect the guns/cannons to the test board LED socket and switch on. Check out my build on YouTube John's model making....https://www.youtube.com/c/JohnsModelmaking