A few assorted responses! Apologies if I miss or don't respond to your specific comment, I did catch up and read everything, though

Was there even a single person on this forum that said "Containment Procedures is a busted skill"?
I don't think that's a requirement; something doesn't need to be "busted" or even imbalanced or w/e to warrant a change! In this particular case, I think feel-wise, its bonus is too much in the early game, doubling the range of even medium-sized fleets, and feels alright later on (which is mostly what the fuel bonus is intended for, to support larger Derelict Ops type fleets). So what I have in mind is lowering the percentage.
(this looks like going from Morrowind fasttravel to Skyrim fasttravel)
Eh, I don't think so, it feels more Morrowind to me.
Limiting it to Black holes and neutron stars seems more reasonable
... but that's a possibility, yeah! I'll keep an eye on it.
As for wormhole and making a gate, it will certainly reduce the mystery of the Domain tech when you are suddently able to make one.
Some assumptions here

I love when games put things outside of the map. I remember an old game, Shellcore Command, that had that as a plot point - go out of bounds, and the things outside of normal space will come after you. I'll admit that when I first played the game, going out into the void to see if there was something there was one of my main objectives. Because I had no idea how fuel mechanics worked, it was a fairly late-game thing.
Ahh, same! Haven't played that game, but it's really cool stuff. Solar Winds had something that felt a lot like that to me, though I don't remember if it actually strictly speaking *was* out of bounds, or not.
Abyssal hyperspace being a very dense syrup doesn't match well with its visuals - which is just an empty black void.
Right now we go from empty foreground with light background ("shallow" hyperspace), to heavy clouds in the foreground (deep hyperspace), to complete emptyness in both fore- and background (abyssal hyperspace). The visual "density" doesn't scale with "depth". It goes from somewhat clear, to super visually busy, to perfectly clear.
I see what you're saying, but it doesn't feel like that to me in-game, at all. As you enter deeper abyssal hyperspace, you see the other stuff - and the backround - fade out, so it doesn't feel like something becoming clear, it feels like you're going someplace dark. And that feeing is reinforced by audio/music changes etc. On a screenshot, of course, all of that gets lost.
(Regardless, it's definitely not a visual progression from clear to clouds to black; the black feels qualitatively different.)
On the comment above, I would like if either we could hire more administrators, or, one administrator could govern all colonies in a system (even if that skill is reduced for other colonies that they are not directly stationed at). For example, the colony where they are 'installed' gets the full production bonus, but other colonies in the system only get 30% of the effective bonus.
Just an idea.
I get where you're coming form, yeah. Not necessarily a bad idea, but just fundamentally, I don't see this game as being about having that many colonies. I realize that's how it can play *now*, what with the lack of an endgame, and with building up more colonies being one of the things to do after the game is "over". But that's not at all how I'm seeing it ultimately go.
Really enjoying the game. I feel like I've run into a dead end in the story aspect of it, but maybe I just need to take my big ships out and start hunting [Redacted] fleets? 
I guess that depends on whether you finished the story! There's... a fair bit of it, both the main story, the Diktat, the new Luddic Church stuff. And of course the [SUPER REDACTED], which if you haven't encountered them yet, I don't want to spoil.