As this mod adds in world gen featuring custom objects, it is not uninstallation safe, please make a backup of your universe files if you're not sure if you'll keep this mod.

For the most part, I even made an integration patch for FU, you can find it here. While both mods should work fine together without it, there are some minor incompatibilities the patch smooths out.

It should, just be sure to note the incompatibilities notice on the main page of the mod for known incompatibility instances.

Once you've repaired the broken broadsword and damaged handgun, you can craft the armor set at the Replicator or any of its upgrades (separator, manipulator, accelerator)

You'll only miss out on the damaged handgun if you aren't using a new character, otherwise you should be fine. And even then, the Damaged Handgun can be obtained by a new NPC that'll show up on the far right end of the ark after beating the Erchius Mining Facility mission.)

They're both based on an unused vanilla dungeon that was added in 1.4 actually, don't believe me? go run a vanilla copy of the game and type "/placedungeon cultistlair" minus the parentheses while in admin mode. Just be sure that you're on some random planet you don't care about when doing this. As for why I just reused this dungeon, there's implications that the vanilla cultist lair dungeon is in fact some abandoned USCM bunker the occasus just co-opted.

Short answer: I was lazy and figured it could work well as a base for a dungeon.
Long answer: I figured that lorewise the research-class freighters weren't purpose built to be research freighters, so retconning them to actually be repurposed troop freighters that made up the bulk of the USCM fleet made sense to me.

It's found in a new microdungeon exclusive to Magma planets, so keep an eye out for fallen meteors with a glowing ore in them. They can also be found in trace amounts in the orbital asteroids biome all planets have and potentially in Astroid Fields too.

Technically you don't, this is a miscellaneous content and tweak mod intended to enhance the vanilla game rather than add a whole new aspect to it.