Well we know the SJ is an Engineer, that was really the big one. We know David made the eggs and even if he didn't the eggs were made/designed by the Engineers as weapons. We know the ship crashes. Getting to how the ship crashed is really the only thing left, which honestly isn't as interesting as who is the SJ and what are the Aliens (both answered).
The size discrepancy between the space jockey and engineers might be a sloppy change made by Ridley, or it might mean that it’s a different creature. (It doesn’t seem like a stretch to think maybe it’s one of the creatures that created the engineers, implying that the engineers model their suits after their gods.)
The decay/fossilization of the space jockey is also an issue, (which I also have an idea on how to fix). Again, is this just Ridley being dumb and lazy or is it something yet to be explained?
We can’t know if we never let him finish telling his story.
And if David made the eggs, how in the hell did they end up on an engineer ship? It’s not like the answers are glaringly obvious and simple. Alien: Awakening does not feel pre-ordained to me as if we all know exactly what’s going to happen.
It’s not like I’m excited to see the biomech touches added. That aspect feels like a chore on a checklist at this point, but it’s still yet another element that leaves this franchise feeling unfinished.
The other big thing that has yet to be explained is what became of David? Right now, he’s just out there somewhere. He’s a villain. I want to see him taken down. Until that happens, he’s basically somewhere in the shadows for the four original movies.
I value this timeline and I love these movies. I want them to work together and I don’t want reboots. Right now, there’s a gap that I don’t know how to fill and it’s so much more complicated than just wondering how one single ship crashed.
And if you’re a Star Wars fan, would it honestly not have bothered you at all if the franchise just stopped cold turkey after Episode II?