Mindset going into the movie, basic plot points. (Potential Spoilers)

After some lurking I have decided to dive in and join the fun. This is my first post so I have placed a spoiler tag for caution so as not to upset things.

Like everyone, I have caught the bug again and my interest levels have peaked ahead of the latest instalment in the Alien franchise. I will be going in to see Covenant in the Cinema at the weekend so I thought I would turn to the Forum for help in fleshing out some kind of guideline for my mind frame heading in there. As close to Canon as possible but only on a few major points. I plan on leaving myself open to forming theories as I go but I would like to have in my head something I'm confident is a pretty solid canon(ish) structure before I crunch my first piece of over priced popcorn.

I watched Prometheus again recently and while I sympathise with those who are bothered by its faults, I actually still really like the film and always have. I can quite happily watch it again and likely will in the near future.

So, focusing on Prometheus leading up to Covenant.

I am of the opinion that the Engineer like humanoid at the beginning (I've always viewed this Engineer and the Elders with it differently to the ones on LV-223 for whatever reason) is sacrificing itself to seed life on "a planet" some time far in the past. Simple enough, I don't think it's ever been anything more than theorised that this planet was earth and we were the future outcome of this sacrifice.

I am leaning to the idea that a higher race of beings than both the Engineers and the Humans created us both, and that there are possibly a couple more similar humanoid species out there with matching DNA. From what I've read this seems safe to believe in I am assuming?.

The Engineers on LV-223 were indeed intent on launching their mission to wipe out mankind on Earth using Bio weapons, but an outbreak or accident of some sort occurred preventing them to do so. This was around the year 2000(ish).

The planet Shaw and David arrive at is populated with a humanoid Engineer like race (although not actually Engineers?, Im not sure I've saw this confirmed).

David makes the decision to unleash hell on these beings with the chemicals in the Engineers ships Cargo hold.

In the time after this and up to the point of arrival on this planet by the Covenant, David has been on this planet experimenting. When the humans on the Covenant are exposed to this planet we are in for major treats involving early versions of Alien type creatures.

This mindset I am in is based on interviews out there and the various trailers we have all seen. Is there anything Canon out there I may have missed that conflicts with these basic points I am working with?.

I have tried to research what I can when I have time but from what I have watched and read this is the basic structure of plot points I am sticking with heading into the movie, with the open minded approach that both questions and answers will present themselves as the movie unfolds.

Anybody got thoughts?. I know there are those on the Forum who have definitely researched deeper than I have, and there are some great theories being discussed on this board.