1: Change to building system because now is annoying with +5/10 planets - NEED the building queue, where you can choose of ALL possible buildings, even if you now cant build them, but they will be at queue, waiting for better day. With this add Storage for EACH planet with minerals/energy etc. (value choice by player) for example 1000. With this game will automatic build buildings from your queue, only using those resources. So no more need to use this... broken sector system. Also this will help A LOT when playing with mods, that add a lot of buildings.
2: change to diplomacy because now is.. no diplomacy between AI and Player. No 'real' trade or anything. They always hate you. Unless you are ridiculously strong compared to them.
3: Change to fight / speed. Now is again, ANNOYING when you rule a big 'country', and time to move from one border to second takes at mid/end game forever.
Game at start should allow only to use Warp, then after research Hyperspace etc. and with that, makes them a lot of faster than old type. So, when player will hit Wormhole at mid/end game, flying speed will be 2-5x faster than is now [compared to current Wormhole]. About fight, You started war or even AI on you, you send your big fleet they run, run, run, run from you. Or better, you are attacked from two borders. Even if you split your fleed, AI still run, run, run form you. THIS IS NOT a GAMEPLAY, this is making player to throw this game out.
4: More live to galaxy, especially Pirates with a unique ship types, that will grow Stonger after attacking your/AI trade ships or other things?. And for ending, sry for bad english.