I would really like to see a new fleet order system. Some way to change the destinations a fleet visits in a system without having to remove all the later orders would be awesome.
Maybe you could make it the jumps had to be in a static order, but you could choose a system that the fleet will be in, and add/remove destinations, and even reorder them without moving them past a jump order on either side.
So, say you had these orders for a Geo Survey ship, starting in Sol:
Standard Transit Proxima Centauri Jump Point
Refuel from colony Proxima Centauri III
Standard Transit Alpha Centauri Jump Point
But then you realize you didn't survey Asteroid #276. It would be awesome if you could choose that you want to change the fleet orders in the Proxima Centauri system, and just insert Geological Survey Asteroid #276 right in the middle of the orders, instead of having to remove later orders, add the new order, then readd the later orders.
And then now you have:
Standard Transit Proxima Centauri Jump Point
Refuel from colony Proxima Centauri III
Geological Survey Asteroid #276
Standard Transit Alpha Centauri Jump Point
But suddenly you notice that it would make sense to survey the asteroid first, then refuel and head on to Alpha Centauri. You could also reorder the intra-system orders, similar to how you can reorder the industry or research queues. You'd need some check to prevent the order from moving past a jump order, so you could get this:
Standard Transit Proxima Centauri Jump Point
Geological Survey Asteroid #276
Refuel from colony Proxima Centauri III
Standard Transit Alpha Centauri Jump Point
but not this:
Geological Survey Asteroid #276
Standard Transit Proxima Centauri Jump Point
Refuel from colony Proxima Centauri III
Standard Transit Alpha Centauri Jump Point
since I'm sure that would break the game.
And then having the ability to remove intra-system orders the same way you can add them.
I'm not sure how difficult it would be to code in, since I'm not sure how you programmed the move orders in the first place, but this would be an awesome functionality, since I tend to plan my orders fairly far into the future, and it's always annoying having to reconstruct them every time I want to make a change early on.