I think bodies here and there would bother the species of the corpses and that's the point by the alien. Does it have one or not? Who can tell?
It might be striving to survive either on the station or through a possible escape. Maybe it's reacting tactically towards what the humans are thinking? Maybe it seeks out alternatives with what it does to implement the most chaos? "Unclouded by conscience, remorse, or delusions of morality."
I don't personally care much about the eggmorphing idea either. The onetime queen facehugger egg by drone idea seems legit but it would also need the best opportunity for the alien and it's like ripley, i suppose, figuring out what to do at the time of events.
The mystery of not knowing how they do certain things is one of the things that makes them special as an alien being. Persistent damage and bodies is what i love seeing in games. The idea of corpses fading away or environment healing itself has always bothered me in many games. If they're on your path showing pain, despair and fear or getting snatched last minute or in some other way surprising you it adds to the atmosphere of the game story.
I wonder if some of the characters you get to know more and relate to will die in the most horrible way?