Perhaps the economy problem could be largely solved by implementing some of the most asked for features for colonization i.e. the ability to designate the primary port and the ability to undo a planned construction before anything is delivered.
Make the primary port use all the installations in a system to determine its economy type and all other ports use the local planet. Furthermore, if you let us redesignate the primary port at will i.e. after construction too then it would let us fix some of the systems already built. This would also naturally reduce the need for multiple star ports in the system so that you could probably drop the doubling of construction points for the third and later ports too - the only point in building one would be if the system had multiple large planets with different economies in which case it would be appropriate to have multiple ports. It may not be a perfect solution but it's one that's easy to understand and hopefully easy to implement.
If we could add and remove planned installations then all you'd need to add to make the economy macinations easily to understand is to add information showing the future predicted economy type for current and planned stations. We can then look at that and, if we do not like what we see, change a planned station. Again it's not a perfect solution and the limit of 5 planned installations and the construction point requirements will stop you simulating an entire system plan but it would help while also giving us a feature a lot of us would really like to see and again it can hopefully just use whatever algorithm FDEV currently have to calculate the economy keeping implementation simple.
Make the primary port use all the installations in a system to determine its economy type and all other ports use the local planet. Furthermore, if you let us redesignate the primary port at will i.e. after construction too then it would let us fix some of the systems already built. This would also naturally reduce the need for multiple star ports in the system so that you could probably drop the doubling of construction points for the third and later ports too - the only point in building one would be if the system had multiple large planets with different economies in which case it would be appropriate to have multiple ports. It may not be a perfect solution but it's one that's easy to understand and hopefully easy to implement.
If we could add and remove planned installations then all you'd need to add to make the economy macinations easily to understand is to add information showing the future predicted economy type for current and planned stations. We can then look at that and, if we do not like what we see, change a planned station. Again it's not a perfect solution and the limit of 5 planned installations and the construction point requirements will stop you simulating an entire system plan but it would help while also giving us a feature a lot of us would really like to see and again it can hopefully just use whatever algorithm FDEV currently have to calculate the economy keeping implementation simple.