Just before I start my TIM run, I'd like to write down a few random thoughts I had on this mod after playing for about a week.
Weapons
The Fed PD guns (Chisel and, uh, the other one) are very flux inefficient for frag PD guns on top of unimpressive damage output, and operating them is very expensive and possibly more dangerous to the ship it's trying to defend than the missiles due to that. I'd strongly recommend setting their flux efficiency to ~0.2 to start and iterating from there.
Letos are kind of a funny missile, quite fast for such a cheap thing but also amazingly inaccurate, making huge sinusoidal weaves that usually misses the target. That's not too bad, but that combines with the fact that its sustained damage is very poor, even before considering it's frag damage type, and because it's charge-based it doesn't synergize well with either FMR or Missile Forge. At only 3 OP, at least I don't feel too bad about mounting it. Still, a heftier missile (for instance, 750 frag- a Frag Harpoon), and perhaps reworking the charge system to synergize with FMR would go a long way to make Letos feel more useful than window dressing without making it high-end.
The medium-size Swarm missile suffers from the "Thumper Effect", in that low-damage frag weapons tend to have their damage absolutely mauled by the residual armor mechanic, dramatically reducing their effective damage even in their home environment (bare hull) compared to other damage types like energy and especially HE. It's a pretty unfortunate scenario, and it hits the Swarm really hard. There's not a ton that can be done for a missile like that, as-is it's probably not worth more than 7 OP, if that.
The Scrapshot guns are quite nice weapons with a fairly unique place in the modiverse. The Light 9OP one I feel is a bit crowded out by both the longer-range 15OP Heavy, and vanilla weaponry around that OP range (800 range HACs and whatnot), but it's by no means unusable. The Large-size Scrapshot is a bit spooky at 1100 range and good flux efficiency, but perhaps it's evened out by its inability to cause real armor damage. Unfortunately, I haven't had to chance to try it out.
I quite like the large energy projectile weapon the mod, seems to be around the right place for a gun of its type and range. Only thing I might recommend looking at is (slightly) enhancing sustained damage and (slightly) reducing flux inefficiency to make it slightly less "extreme" in terms of range-to-efficiency and minimum sustained DPS, if that makes sense.
Overall, I'm quite impressed with the weapon artwork. There's a few FTL weapons I recognize, and others that appear to be entirely new for Star Sector. The Fed seems to make heavy use of weapon charge mechanics, and generally benefit a lot from Expanded Magazines as a result.
Capital Ships
Unfortunately, I was unable to sufficiently test Cruisers and smaller, so I'll only be able to make comments on the Capital ships.
The Rebellion-class, clearly based on the iconic Rebel Flagship. As it turns out, a powerful Battleship in Star Sector as well, if only in one direction. Making the limited-traverse turrets Synergies instead of the frontal hardpoints is an interesting design decision, as is the rear-facing Paladin. Ship system feels like a more clumsy version of Maneuvering Jets, though that might be better for balance, I don't know. Overall, a pretty fun ship.
The Union-class Battlecarrier turned out to be a really fun ship to outfit and fight with, despite limited modularity in its carrier slots. It's my favorite among the 3 Fed caps name-wise and aesthetically, and carries a competent weapon loadout for its weight class. The built-in Pilums seems like an unusual choice, though.
The Accordant-class Battlecruiser is kind of unusual aesthetically. Armament is similar to the Union-class, but replaces the 4 fighter bays with another Large Missile. I'd almost describe it as a foward-facing Conquest, though it does have energy broadsides that... don't seem to contribute much? It's also more expensive than the Union-class in terms of DP, IIRC. I feel this cap needs the most work put into it, out of the three
I'd strongly recommend increasing the burn speed of both the Accordant-class and Union-class to 8, to match fast caps like the Conquest and Odyssey (in addition to other mod Caps).
Unsolicited Suggestions
In the unlikely chance you're open to random ideas of things that could be implemented from FTL, here's a few ideas I've had:
Boarding Drone "missiles": A utility weapon mounted in missile slots (probably small, *maybe* medium), small amount of Frag damage, with additional enduring effects if the "missile" is lucky enough to impact the armor/hull, for a long (but probably not infinite) period of time, say a minute or so. Effects could include periodic EMP bursts generating on the ship (EMP drones), increased weapon repair times due to boarding action, random malfunctions similar to that experienced at low CR, or a combination of these effects.
Hacking Drone System: Built-in system, similar to the Boarding Drone missile but activated by systems (and as such, non-modular). Similar effects if the system hits the target ship's exposed hull: big EMP bursts when activated, random malfunctions, or both. Probably needs a limited number of uses until you need to send the drone again to prevent you from endlessly sabotaging the same ship.
Boarding Teleporter: Built-in system. Sends a boarding party to sabotage a target ship within range, causing effects over time similar to the Boarding Drone but without having to land a hit on the hull. Likely the easiest to implement out of the three.
Drone Control Hullmod + LPC-ifying drones: As a nod to FTL's federation's usage of drones, a Drone Control built-in hullmod would provide additional enhancement to 0-crew fighters (aka Drones), such as OP cost reductions or other bonuses, without stopping Carriers from using manned craft if they so choose. The built-in drones on current ships are neat, but (IMO) I kind of like the flexibility of modular equipment, so I'd greatly appreciate if the Federation received a drone LPC or 2 for installation on these or non-Fed ships.
Secondary Shield faction hullmod: A hullmod for cruiser-grade and capital-grade Federation ships. Adds a secondary shield if there are none, or enhances an existing secondary shield (arc coverage, absorptive capacity & dissipation, etc). Understandably wouldn't be the easiest thing to implement, if it's possible. Might be possible using a system similar to how Interstellar Imperium does their specialty package, switching out a base ship to a similar skin with different charracterristics?