There was a lot of work put into Star control origins. The game itself and its story allow a large room of possibilities to be explored at the end. 

I'd say do an expansion but can it be done so it takes place 'after' the story?

Is this feasible or would this be considered an sequel? 

I am looking forward to seeing what evolves. 

I think another expansion is a must. Develop a lore a bit more, add some additional features (Quasi Space, Below Space (even if these are just additional @layers@ of the main hyperspace (sector) map) etc.), more assets across the whole board (stars, planet types and planet visuals (where are the ringed planets????, comets??, black holes), ruins, stations, ships, modules, aliens, critters, even mineral types), tweak the tools a bit. You can still start your work on the sequel in the meantime:)

I think there must be some form of contest for the modders, writers, visual artists, composers, even voice actors. The best story mod, best ship, best new module, best art, game tune etc. More attention shall be drawn to various mods. I am sure that many will be ready to surrender and waive any claims to proceeds if their assets of any form get included in the official game

Any licensed universes around? babylon 5, star wars, halo, warhammer 40k, star trek, mass effect, Lexx, Wing Commander, GalCiv, BattleTech, X-Com, Age of Wonders Planetfall, Sins of the Solar Empire, Known Space, Starflight etc.? Any total conversions? A remake of SC2 (yeah-yeah - legal issues...)?

I think that yes, SCO needs more expansions. Currently there is a stark contrast in quality between the main story and the side quests. While not all optional content in SCO feels as boring and copypasted as the "wrecked ships" you find all over the Scryve Sector on random planets (why did you decide to add them anyway? It's already easy to replenish your fleet as it is), SCO definitely needs more good storylines - more exciting new races, more mysteries solved, more mysteries introduced. I fully agree with you that fetch quests aren't what this game needs. As of now, the main storyline of SCO is way too short.

You've also talked in your pre-release journal how alien ships in SCO don't just fly around randomly - they carry out specific tasks. I think the game needs to emphasize this more, to exploit the alien ships' AI for the purposes of the story - like, have entire storylines that unfold differently based on how the aliens act.

What I also didn't like in SCO was the lack of meaningful dialogue choices in many situations ("It's love, isn't it?" and all that - okay, I understand that was comic relief). I remember you talking about how much freedom SCO gives to the player, how one doesn't have to be the perfect noble hero to win... Only there are already tons of games on the market that offer this kind of freedom to the player, and the moral choices you have in SCO are rather lackluster, as there is always a very clear-cut good versus evil choice, and the only reason you'd want to make an evil choice is either because you're lazy or if you really want to do evil for the sake of evil. There are only two exceptions to that I can think of. The first is unleashing the Xraki, but that choice is forced on you, there is nothing you can do about it. The other is allying with the Overmind Trandals, but the game doesn't show any real impact of that choice beyond Trandal ships starting to fly around Scryve space once you win. I'd prefer to have genuine, difficult moral dilemmas where there is no obvious good choice.

Things I'd like to see for SC:O

* Enhanced multiplayer support

Maybe something as simple as being able to play fleet battles versus the computer while waiting in the queue for a human opponent.
Maybe 2v2 fleet battles.
Maybe some type of 1v1 local multiplayer strategy game, simplistic galactic conquest with a lot of fleet battles.
Maybe online multiplayer X4 style with each player controlling one race.
Maybe online or local multiplayer coop adventure mode.

* A build that works on wine / proton or linux somehow.

* Additional quality of life improvements for the UI (there has been progress, thanks!)

I agree with the general consensus that a more fleshed out universe is in order.

I also think, as a practical matter, that we need to have some more interesting things to do on planets than what we have now.  On the Star Control discord, I've mentioned in the past having landing parties.  

The issue on landing parties is, of course, budget and whether we leave that for a sequel or not.