It is possible to grab weapons from frozen corpses. If it is cold enough to freeze a corpse for decades, a weapon wouldn't fare any better.
Mistakes in in-game subtitles.
Grammar mistakes in dialogue.
The maximum ammunition for each weapon should be a multiple of the capacity for each magazine, since it doesn't make sense to have partially filled magazines; however, the maximum ammunition doesn't always equal a multiple of the magazine size for each weapon.
There is at least one light on in Azusa, a base that has been abandoned for some 25 years or more.
Weapons once used exclusively by the DB units now seem to be in official use with the C.O.G. forces. Given this, they should be equipped with some kind of sight.
Despite being pretty much the same weapon, the Lancer GL and the Lancer have different ammunition.
Despite being in cold weather, no one is wearing a hood.
Marcus Fenix says that his father let Baird in on a few secrets before he died. There wasn't enough time for this to have happened.
Considering that Azusa is a remote island, there should not have been Juvies and Drones because there would not have been any humans left on the island to convert to Juvies and Drones.
Lena could have freed Norsko yet instead simply left him in a pod.
It is unlikely that the research facility under the ice would have been able to keep power for so many years.