The Colonial Marines' normal opposition consists of Space Pirates
Obviously, the Colonial Marines don't exist for the sole purpose of fighting Xenomorphs, who are mostly an Outside-Context Problem
as far as most normal humans in the Alien universe are concerned. But given the amount of precious cargo moving through space on Weyland-Yutani and other companies' cargo ships, it wouldn't be surprising if piracy was a big thing in this setting, sort of like it is in present-day Somalia
. This would also make sense symbolically, seeing as how one of the real life marine's
first wars was against a group of pirates
. The Law of Conservation of Detail
was in effect so the space pirates and the marine corps' role in fighting them went unmentioned, but needless to say Apone
, and the and the rest of the squad
have probably killed quite a few of them.
- It should also be noted that the United States Marine Corps was founded specifically to combat the Barbary Pirates. And since the United States Colonial Marines are basically a sci-fi version of the USMC, it would be fitting if one of their duties was combating piracy.
Carter Burke was given the coordinates to the Derelict by same person who wrote Special Order 937
How did Carter Burke know where to look for the Derelict? While it's possible that Ripley knew the coordinates for the Derelict and presented it to the board of inquiry, given the lack of data from the Nostromo mission and the events that took place immediately after, it's unlikely Ripley knew. So again, how did he know? Someone anonymously gave Burke the coordinates and a (subtle) financial incentive to check. Who? David. The whole pitch about the Bioweapons Division is just a cover to get the Xenomorph back to Earth. Once there, he could sabotage any containment measures or security the facility had and cause the alien to break out and spread.
The Queen wasn't the only Alien to hitch a ride on the dropship
Let's be honest here, even if the Queen could still lay an egg or two in her condition she still had no opportunity to actually so into the larger ship and hide them. Therefore there must have been at least one other Alien to have also come along (there would be enough time for one or two to have climbed up the elevator shaft and jumped on before the dropship could get away, it did get snagged on debris after all) who were then sent off to secure the eggs while the Queen dealt with Ripley and Newt herself.
The whole point of the colony was to find the derelict ship
Yes, of course the modern W-Y board pretends not to know anything about the incident with Ripley and her ship, if they're corrupt enough to sacrifice a half-dozen people in the first place then dumping the blame for the loss of the ship and writing her off as delusional would be nothing to them.
There's no good reason to have a colony on LV-426, it's hostile terrain, dangerous weather and no mention of anything useable or useful. What it does is allow the company to maintain a presence on the planet without arousing suspicion about what they're doing. No matter how long it takes the ship will still be there, the eggs will still be there and sooner or later the colonists are going to stumble across it.