Simply moving orders up and down within the list would be physically easy from a coding point of view but the potential dangers are massive in terms of unexpected bugs. The orders are recorded in a list in the database with a simple MoveOrder field that controls the order in which they are executed. If you change the numbers in this field, it changes the order in which the orders are carried out. However, there is a lot more to the orders system. When you add an order, such as Jump into Sol, the program then looks at where your ship is and lists all the possible orders on the Fleet window that can take place based on where you will be once that order is carried out. If you add a second order the program re-evaluates everything and presents another set of potential orders based on where you will be after the second order is carried out.
As a simple example imagine you had the order list: Load colonists on Earth, Transit into Proxima, Unload Colonists on Proxima Prime. If you move any of those orders further up or down the list, then it will no longer work. You can imagine the potential for unexpected screw-ups and ships wandering in circles with more complex orders.
Besides, I have already implemented a new feature for v4.1 that will facilitate much quicker ordering. You can bring up a list of all colonies and if you are within four jumps (maybe further in the future) you can give an order for that colony and Aurora will fill in all the intervening orders automatically. For example, in my own game if I load a freighter with mines in Mars orbit and want to send it to Xiamen-Kan, four jumps away, I can show the list of colonies and just give the unload order to Xiamen-Kan. Aurora will fill in Transit into Sparta, Transit into Chicago, Transit into Denver and Transit into Xia before the unload order.
Steve