With an expansion comes time for the game to be improved all around on some flaws.  This isn't just time to improve on and twink the new stuff with the expansion it's also time to fix some minor issues with the original game.  Thats why games have expansions to improve on the old and new. 

-  Capital ships although stronger then all the other ships they die way to fast.  The Hull points need to be increased on all of them along with shields so they are truely a capital ship.  At the same time the cost of purchasing a new capital ship needs to be double of what is is now.  These ships shouldn't be as common as they are especially early on in a game.  There attack power should remain the same as it is as to not make them to strong but a defense boost is definately needed.

-  Starbases their attack range needs to expand throughout the entire gravity well.  The build time is way to fast these structures should be formidable but right now they are bypassed with ease.  Ensure only one can be in a a single planetary area at one time.  I'm not sure IC's intent of these structures but right now its just a building. Either they are supposed to be a juggernaut structure which will take a nice size fleet to destroy or they are minor boost to a planet defense.  There has to be a big fish, little fish scenario going on.  Where a Starbase> Capital Ship> Cruisers> Frigates> Strike planes etc.   Starbases just like capital ships need a defensive boost as to make them more formidable.

-  Mines plain and simple should have a build limit.  They should be a fill gap for where you dont have turrets protecting an area then you place mines not use mines as a sole defensive mechanism.

-  Boost the pirates abilities to use larger ships when assaulting a player.  Right now they do nothing but feed experience to boost your capital ship up in levels.  They don't need to be to strong but right now they are a joke.  Maybe add fighters/ bombers to Pirate fleets as an example.

This is just a start that in my mind needs improving and i'll add to the list as I have time to play the expansion some more.