I've got some A3 imaginings. I'll post here since your main thread is off-site. Might be some small thing to be gleaned.
Initially, I had a happy ending. I grew less certain as things went on.
Now I'm working from the haunted ending version:
...Private Jonathan Hicks has received a posthumous promotion to Warrant officer of the highest grade and is recommended for the Colonial Congress Medal of Honor...and Captain Ellen Ripley...has been nominated to receive the United Worlds Medal of Humanity... for her selfless... The government has vowed that it will not attempt to reclaim this ship... We have set course for High Singapore in the hope of purchasing quasi-ligitimate registration and liscensing. This is ___ Newt ___, Acting Captain of the Rogue Ship Sulaco....
Twin themes of a hyper-aggressive alien nation on a blitzkrieg for lebensraum, and the complete alienation of the characters not only from the company or military, but all humanity.
It could be that they discover their betrayal towards the end of the film and have to ride off into the sunset. Alternatively, a distrustful Ripley might have programmed to come out of hibernation before reaching their destination and learned that the colonial, company, and military authorities have, in an act of frontier justice, sentenced them to death in absentia after assuming they fled deep.
After any necessary prologue, we see the gang coming out of stasis and going for their meal (everyone gets a bad case of the munchies shortly after waking from stasis). Their computer woke them after recieving a distress call. A ruffled looking Bishop, with too many patches with adapted parts and losses of vital fluid, goes to investigate.
At the meal, we get to meet the crew of the R.S. Sulaco (formerly U.S.S. Sulaco.) Maybe a few other ne'er-do-wells and possibly another android escaping slavery. We learn of various motivations and the difficulties of keeping the ship in commission (now the ship has a 3D printer that produces parts and fittings that must be replaced too often.) We meet 18-20 Newt. She is girl-next-door pretty under tangled hair and patched overalls. Captain Ripely is an inverted Uncle Owen and Hicks is an uncertain Aunt Beru. An argument ensues. Ripley is very anxious to find a way to safely send Newt to University (authorities are afraid she is a witness.)Newt has rejected "regular" society and is very attached to ship and crew. Newt argues that she would only go to commercial pilot academy and then return to the ship anyway, so why bother?
Bishop returns and we learn of the great dilemma. A colony world of hundreds of thousands has sent a distress signal. They are not specific, but it sounds like Earnest T. Doublesmiles. Their plan is to evacuate all children too young to fight with their mothers and they require all ships within range to come to orbit. Newt argues it must be a trick. The moment they take on refugees they will be trapped in orbit. The Sulaco could sustain more than a thousand refugees in orbit. If they go to the planet, the phoney case is so strong against them that they will be arrested and put to death. Ripley and Hicks decide to answer the call on condition that they be allowed to go to the surface with weapons and help the colonists and that the Sulaco will remain under Newt's control with any crew that decides to stay with the ship.
When they reach the surface they discover that the planet has only a loose militia to discourage small raids, some police, a couple of Marines manning a communication post or something, and no hunting weapons because there is nothing to hunt. Maybe it's the moon of a gas giant going into eclipse or has slow rotation or they build underground to hide from cosmic rays or something. They get a rough welcome. The Marines want to frag Hicks. A young corporal alot like Hicks stops it because he doesn't have time to train the civies but vows to frag him when it's over.
The usual festivities. We learn that the Aliens have a way to escape and spread like wildfire if not stopped here. It's a company owned colony. Newt and Bishop show up in the drop ship. Bishop downloads info on the company plan to spread the aliens. More fighting. Hicks sacrifices himself to save Newt and the corporal. Ripley sacrifices herself to stop the spread to other worlds. Newt and the corporal must face whats left.
That's it in broad strokes. :)
EDIT: A cylander or generation ship are alternatives to a planet.