This post will be focusing on the exploration/combat music, i have no problem with the faction music, my problem with the exploration music, it becomes extremely repetitive after a while, and it's cheerful way doesn't fit with the games overall dark tone, i think what contributes heavily to the music becoming repetitive is the fact that it's
constantly playing, there should be some more quiter ambitious/eerie music inbetween there, another suggestion, have faction specific music play in systems dominated by a faction, i like the idea of sneaking around a luddic system and some ominous music playing. Have a look at Fallout New Vegas sound design, in my opinion they nailed it,
, another thing i have noticed is that the fleet encounter music is good, but you will barely ever hear even 1/4th of it because theres little to no reason to stick around in the fleet encounter menu, i however don't have any suggestions for that, and my last point is, the combat music just feels kind of off, it's always playing in combat, regardless of situation, and when the music is done it just kind if akwardly stops, a good example of combat sound design would be star wars empire at war, in that game there would be tense music playing in combat when there is no fighting, once fighting starts it plays the actual combat music,
, perhaps you can take some inspiration off of these games, cheers!