Yeah the crew's cavalier attitude towards the planet and it's alien ship did kind of bug me a bit. Given the immense magnitude
of the discovery, and the fact they were all a bunch of scientists, I would have expected them to be a lot more awestruck and amazed than they were (it seemed like Shaw and her bf were the only ones truly excited to be there).
And the way they rushed directly into the structure without AT LEAST doing a quick survey of the exterior seemed very odd and unscientific as well.
But I also realize this is a big budget summer movie that needs to move at a decent speed, so you're going to have to take some liberties with the science. You can't have the crew acting TOO careful and cautious, or else they'd never get themselves killed or infected with nasty alien viruses in the first place.