Andrew is correct on the turning issue.
As said, in this example the Emperor cannot turn. It moves 7,5 cm straightforward. If it goes on Special Orders Burn Retros it can turn at any point.Q1 It says when a Tyranid ship with claws latches unto a ship thats larger that ship will move at half speed. So lets say they would attack an Emperor Battleship. It would move 7,5cm max. So it wouldnt be able to turn? Since Battleships need to move 15cm before being able to make a turn?
A1. I believe you may always make a turn at the end of your movement.