I would also consider how the xenomorphs might have affected the planet itself, maybe creating entire ”cities” of nests. I imagine something looking like giant termite mounds (have a look at this ”cathedral”: https://sv.m.wikipedia.org/wiki/Fil:Cat ... wbooks.jpg
). There might also be some kind if fast evolution going on. I would assume that the creatures could become a lot smarter, creating and even building things never seen before. Maybe a fast growing biomechanical ”antenna tower” of some form, perhaps for long distance telepathy? I can also see their ”nest cities” growing organic and take new forms: glowing, strange ”polluting”, giving birth to derilicts and maybe even some form of bizarre eyeless humans, coming out of eggs... The xenomorphs might be able to create an entire - and fast developing - biomechanical ecosystem with living things and beings. It’s life in a way and a scale that people from Earth haven’t seen before...
Finally, since the xenomorphs are developing, they may offer something to humans. Probably they understand that they might be attacked. I also imagine that they could threat mankind by developing new weapons, that could be fired towards Earth. Maybe some kind of biomechanical ”seed missiles” full of nasty organisms? That could be the reason why the planet hasn’t been nuked yet. The negotiation with an entire collective of queens is probably really bizarre, aggresive and unpredictable. Maybe they are able to ”fire” entire ”nest cathedrals” against Earth? Or contacting even more powerful allies somewhere far away?
So what we have seen in the movies is just a very ”humble” beginning... The xenomorphs are truly nasty beings with a potential unknown to mankind. If you think the become too dangerous, just make them start a civil war and/or suffer from some kind of powerful virus.