These features would be nice.

[AndonSage]

>> If you cannot get there in 1 turn and the next turn they move ( extremely likely ) your ship doesn't follow, you have to set the order again. <<

This won't help the entire problem, but one thing you can do is cancel your fleet's orders after moving towards the other fleet (if you don't make it in one turn). This way you won't use up movement points the next turn when they go somewhere else, and you can give your fleet orders to attack again, at the enemy's new location. Note that if they are faster than you, you probably won't catch them anyway if they are moving away from you.

AndonSage