Like I said the other day, really enjoying this mod. Thought I would dump my feedback on factions:
XLE seem like they have the worst ships compared with the other 3 factions, mostly for Flux dissipation reasons, as their ratio of max flux to flux dissipation is 20:1 when most ships are 10:1 or lower (UIN generally has 5:1). Their cargo ships also have a much higher logistic value than other factions. Seems like just giving them more flux dissipation to work with, or increasing their max flux would be a great buff. As is, if you mount any energy weapons, you tend to build up too much Flux, and have to spend a long time venting. Frontal attack ships seem much more like brawling ships, which could use high flux dissipation for energy weapons.
ISA have far and away the best frigates and destroyers in the game. They have good Flux capacity and dissipation, and good shields. The Extended Missile Racks allow for a lot of long range support. The Illinois is easily one of the best destroyers in the game, capable of soloing a Moscow if piloted well. Indiana has one of the highest Flux capacities, with good dissipation, meaning its shield is incredibly tough. The C class makes for amazing missile spam.
I was a little surprised to not see a larger carrier than the Idaho, since their combat doctrine would call for missile spam and well armed frigates and destroyers (providing the missile spam), with the rest of the fleet playing defensive. Seems like a supercarrier capital ship would be fitting.
My destroyer composition was just a bunch (6+) of Indiana-C classes providing long range support, and an Illinois as my flagship, mostly holding the other fleet in one place. It could effectively take on any of the RSF battle fleets, although the ones with 2 Moscows tended to get a little hairy towards the end when the Indianas run out of missiles.
RSF don't seem like they are powerful until you reach the larger ships. With the weak forward facing shields, most smaller RSF ships are vulnerable to missiles and assault craft. Larger ships are quite tough, since they can spread missile damage across their armor, and can mount more point defense. Flares aren't always reliable to handle missiles on the smaller craft, but they do help. The lack of omni-shields really hurt for dealing with missile fire.
UIN are designed for broadside engagements, but they end up with the highest Flux dissipation, meaning you can mount just about any weapons you want and not build Flux. Seems like the XLE approach of higher Flux capacity, but low Flux dissipation is more fitting for a true broadside, rather than a brawl. Fortress Shields help avoid a brawl rather than promote them, and also function as effective anti-missile defenses. Particle Beams are a little on the powerful side, since you can just outrange most weapons with them, and simply keep pulling back from the enemy.
FFS I have not played with as much, but what ships they do have seem quite effective. I don't think they match up against the ISA frigates and destroyers, but probably are the second best.
Marauders have extreme vulnerability to missiles due to lack of shields. Pirates just have civilian ships, so they don't match up ship for ship. Black Widows might be slightly better at fighting UIN, since the UIN tends to pack energy weapons, but I feel like they should have a combat doctrine of speed/mobility, since they are raiders trying to get in and out quick.
I don't know if maybe I just don't understand how the XLE are supposed to fight, but I can't make their ships work for me.