Well there's the classic criticism of characters that are either underdeveloped and/or do not react the same way they had previously been depicted to the audience. Best example being the xeno-biologist and the geologist. The first being scared of a 2000 year old alien but then later cooing at a space snake like it were a house cat. Then there's the geogist who's only purpose apparently was to map out everything and despite being the one who built the map via his "pups", proceeds to get lost.
That classic criticism is the weakest. The xeno-biologist was behaving entirely in-line with his character. I could go on and in depth, but you basically threw a gish-gallop at me. Suffice to say: his character was perfectly well developed, and he behaved in line with his character the entire time. A brief sketch to illustrate: Vickers is convinced that this is a bullshit run into deep space going no where. She is perfectly up front about that, and that means that any biologist going along would know. This means that the biologist (regardless of anything else we know) was a biologist who signed up for a mission going farther than any mission has ever gone, which is extremely dangerous, which will require a very long time in hypersleep, fully expecting to arrive and not be needed for a god-damned thing. You know who takes that job?
Not a very good biologist.
As for the rest of what he does--he's obviously trying to make friends. He's socially awkward as hell, and he really wants the approval of the geologist. Everything about his character up to the moment of his death is focused on that.
What does that leave us? A biologist that is probably not the greatest in his field who is trying to show off to impress this guy he's been trying to impress from the moment he was on camera.
As for the dead alien--it's obvious that the entire idea of the engineer theory freaks him out. That's obvious again from the first moment he's on screen. The idea of intelligent alien life is not something he's mentally equipped to handle. A snake is just another animal. There is nothing inconsistent or problematic in that.
Then there's the geogist who's only purpose apparently was to map out everything and despite being the one who built the map via his "pups", proceeds to get lost.
That is explained directly in the film. The storm cut of their connection to the ship, and that means that he lost access to the map. In case it wasn't clear to you--the probes sent data back to the ship; the map was created by the ship's computer; the map was then transmitted down to the ground crew. No connection; no map.
I'm going to stop there, because I will hit the word count cap if I keep going. I will just let this suffice to show that "the classic criticism," the one that should be strongest, is utter and total bullshit. Only a lazy, passive viewer could watch the movie and not pick up on those details, as they are being telegraphed fucking constantly when the characters are on screen.
Re: Vickers--you completely misunderstood her purpose in the plot. Her purpose was to provide a foil to Weyland so the audience could peace together his character, his motives, and his beliefs.
Also--nothing absurd about her death. The ship rolling was unnecessary cgi masturbation, but that is a design complaint. From a story / plot point, there is nothing wrong with her death. She was panicked, she ran, she died. The end.
Also, Weyland's death is supposed to be rushed and confusing. In case you didn't notice in Covenant, the purpose of the trilogy is to piece together Weyland's character, and juxtapose his character and his choices against the consequences of those actions.
I said I was stopping earlier, but I'm really stopping this time.
Your entire critique boils down simply: you didn't understand the point of the fucking movie. And I will counter your assured rebut ahead of time:
Have you read Milton's Paradise Lost, and were you familiar with Shelley's "Ozymandias" before seeing Covenant?
If not, then you don't even have the most basic pieces of the information you need to understand or criticize the film, because you don't know what the movie's themes are.