I enjoy the discussion of lore, so I'll hop in as well.
1. Regarding Pirates, the faction description in-game describes them as "not technically a unified faction." Their appellation is exogenous and is more about their hostility to you and the major factions than it is about the markets' relationships with each other.
The Pirate "faction" markets are all small populations (3 or 4) but fall into a few different categories. I'm sure you've read all their lore, but bear with me. There are a few different reasons they haven't been absorbed:
- Little of value (Garnir, Kanni) and/or too polluted to be practically habitable (Lost Astropolis)
- Mercenaries (Donn for Tri-Tachyon mercenaries, Thulian Raider Base for the conflicts among gens of the Persean League)
- Umbra: see Usurper questline
- Too fortified (Kanta's Den) or too difficult to conquer outright (Kapteyn Starworks)
Kapteyn Starworks is an interesting exception. Like Laicalle Habitat in the same system, it was conquered by Warlord Leonis, but Laicalle Habitat seems to have voluntarily joined the Persean League, albeit under threat of conquest.
The tutorial actually has Derinkuyu Mining Station switch from Pirate control to Independent. I would like more opportunities for things like that. I think it would be very neat for the player faction to absorb one or two of the pirate markets.
I imagine Kanta's Den, Garnir, Kanni, and Lost Astropolis would remain Pirate no matter what you did because no faction is really motivated to absorb them. Kanta can easily dominate them (and the pop-up bases outside the core), but the others do seem to have their own power base or benefactor.
As I was writing this, I came more around to your line of thinking about the Pirates as heterogeneous, but I still think the name is fine.
2. Independents are fine, and the faction description in-game describes them as "not a unified faction as such." Their faction description as a whole shouts "non-aligned movement" to me.
3. My impression of the sector is that it's like a factory cut off from anyone who can actually make molds or heavy equipment; however, they still have plenty of ore to pour into the molds. When some critical terraforming technology becomes defunct, the technological gap is so large that there is no hope of a replacement, but they do have blueprints for ships and plenty of metal.
That said, the problem late-game is not that the frigate/destroyer fleets don't exist but rather that you have no incentive to engage them.
4. Haven't played with colony threats at all, somehow haven't made a colony since they got added.
5. I think David has ably answered the question of the Hegemony. I do take your point about the name, though, and think the faction description could reflect the historical reason for the name.
For my part, I can easily imagine the Pearseans sneeringly referring to the XIV Battlegroup as the so-called-Hegemony and for the name to stick when the XIV Battlegroup arrived 48 years after the Collapse and declared their hegemony over a Persean sector controlled largely by warlords. I wouldn't expect the XIV Battlegroup to object to being called the Hegemony.
The "Sindrian Diktat" is evidently an allusion to the Eventide Diktat, meant to legitimate Andrada as Diktat Executor for life. It contrasts to the Eventide Diktat as being a Persean concern instead of a reference to the Domain. I don't have an issue with it, though I do understand your point. It's a bit odd, but the name makes sense if you consider it as coming from the leader's title, which makes sense for the self-aggrandizing Andrada.
