There was a Preadalien in the earlier AVP:DUEL comic
The predator did use armor, just not a bunch!
You don't have to break rules to make a good R-rated film! Seems like they may just be trying to "push the limit". Directors these days have to either cut a bunch or corners to make it PG-13 or slunk in ridiculous gore to make it "Unrated". Hopefully these guys won't screw around with either of the above (not a chance).
The characters sound like they could very easliy be "generic idiots".
BTW, how does this take place on Earth? If that were so then wouldn't the alien already be a documented species in the first ALIEN?