I think there's a lot they could do with exploring facets of a hunter-based species that has encountered mankind throughout it's existence. Heck, the best parts of P2 were the moments that shed insight into their culture and code of honor. TNG did something similar with the Klingons. What they really need to do, though, is go all in and move the series beyond a modern day setting. Either do a period film set during WW2, the Viking age or feudal Japan (or a series of films set in different periods) where you explore their interactions with our past (actually, a prequel film that ultimately explains the origin of the gun they give Danny Glover would be an awesome little connection- you might even be able to use Glover in a framing story) or go into the future concurrent with the Aliens universe and explore their role in that timeframe where you might be able to draw connections to the broader Prometheus/playing gods/picking up the tools of fallen gods angle. But what they do need to do is try to stop retreading P1. Yes, have "those moments" but the "same thing, different guy" approach were what made the sequels less appealing than the original, despite the parts they had that distinguished them. P1 is one of the greatest action films ever made, so it's understandable why they'd want to imitate it so closely but being so conservative with their approach has limited things. P3, to its credit, at least tried to open things up with the game planet and clan blood feuds, even if that gets lost amongst too many "homage" moments.