The movie has 3D... I have 7+ questions

Rating: 3/10 (22 June 2012)

I saw it and I didn't like it. What is more, I am so disappointed that I am posting now my first ever review in IMDb just, for the sake of it. Too much is missing there, and above all - logic. It rather looks like a bad patchwork.
OK, I know this is meant for entertainment but still the pseudo-science in this movie is brought to unbelievable lengths. So, here are my 7+ questions:
1) Where is the logic behind the following: The engineer that "infected" the Earth with his DNA, was he some DNA-kamikaze? Come on, does that mean all life on Earth should have human DNA in it?
2)Where is the logic behind the following: The way the human scientists approached the unexplored planet, just flying over to see any artificial signs on its surface. Is a planet supposed to be that easy to explore? Like, let's fly over it and see from a bird's eye view if we can find something out? Really?
3) Where is the logic behind the following: On the 5th second of analyzing the atmosphere in the forsaken alien ship, and they removed their helmets, come on?
4) Where is the logic behind the following: In order to exterminate humans on Earth, the "engineers" had created some new alien-snakes? The ones that sow life on Earth could not think of anything smarter?
5) Where is the logic behind the following: The first thing the awakened "engineer" did was to start his ship towards the Earth to destroy life on it? Why did he have to spend 2000 years in cryostasis in the first place?
6)Where is the logic behind the following: The android infecting its superior with the alien DNA? Was the android curios? Any motives behind it? Or what was its motive to await the alien baby of the female doctor?
7) Where is the logic behind the following: The android at the end was trying to bargain with Elizabeth over its "life"? Like "please help me and I will help you"? Was it scared?
And I just don't want to go through all the goofs there...
I am sorry but I really wanted to enjoy this movie... and at the end, I did not...