So how is an alien used as a weapon?

Maybe they would try to do what General Spears had in mind, trying to control the aliens via the Queen. If they get the Queen to cooperate through fear of the eggs being destroyed, then the drones will obey the Queen. Also, they could deploy them on a planet they wanted taken out (not sure how they would reclaim that planet), or maybe a space station or base owned by a rival company like Seegson.

I never quite bought the bioweapon aspect of the story. Luckily it was primarily Cameron's idea introduced in the mediocre sequel, so it didn't damage the original Scott's movie/story. If I remember correctly the company was interested in extra terrestrial species in the first movie (wouldn't you be?), but not as a weapon. The almighty company introduced in the sequels could have picked the alien just fine without involving Ripley.

Dr Wren in Resurrection mentions that the potential for the species went beyond “urban pacification.” They talked about studying the alien to develop new alloys and vaccines. Basically because the alien was the ultimate organism, it had potential to be used not as a weapon itself, but its biology could be studied to improve weapon and medical technology they already had.

Slow, LOL?! It wiped out the entire colony on LV-426 in a matter of days once the eggs were exposed to the population. It killed every marine sent in for followup except Hicks too.

My interpretation is that the company wanted to land ownership rights to any possible discover of alien technology overall. Having such a thing in their possession would elevate their stock price and yield a great amount of power, not just influence.

Look at it thru a modern perspective with someone like Elon Musk and his Mission to Mars program finding ancient alien technology and having first rights to it or better yet a full partnership with the US Federal Government. There would be no competition to out do that and he'd in a position like Weylan/Yutani

Thinking like a Hollywood scriptwriter...

i. Use them as advance infantry. Drop them into a zone, let them wreak havoc... both physical and psychological. You could even augment them with weaponry on top of their natural abilities.

ii. In reverse, use them as part of a scorched earth policy. If you must retreat, leave them behind to at least deny the enemy the use of the territory.

iii. Use them for specific environments that make the best use of their characteristics. They are nimble, are able to communicate via some hive mind, can see in the dark iirc, are pretty strong, grow FAST... they would be ideal for restricted environments such as caves, industrial complexes (where they blend in naturally with piping and machinery). The third? fourth? movie demonstrated that they are pretty effective underwater, seemingly not to need to breathe for long periods of time.

iv. They could simply study their physiology with a mind to developing weapons that human soldiers could use, similar to how scientists have studied spider silk to create synthetic versions that can be adapted it for other purposes. Their blood is acid... could that be adapted for human use? How do they move in the dark without eyes, etc?

v. Genetic engineering... can they be combined with other lifeforms to create a useful weapon? Wasn't there a dog-like variation in the one set in a prison?

Any other ideas?

You drop some eggs on a planet and wait for the inevitable breeding.

You take it to a convention of the demorats and let it do its thing.