I don't understand your problem
seems pretty fine hereshipShooter.capx
here I made the ship volontarily shot at 90 degree to test the "bullet should follow the ship"
And even if you have the weird impression it goes sideway, if you think horizontally it follow the ship quite well.ship90degreeShooter.capx
The impression you have that the bullet doesn't follow, might be caused by the fact that you are accelerating. Your bullet just get the instant velocity the moment you shoot. You can see that in the second capx, when you attain maxSpeed, bullets follow the ship. But when you change direction and your velocity is not constant anymore, the bullet doesn't follow anymore.
That's an expected behavior