Irrational behaviour, logical flaws and plot holes

Rating: 4/10 (17 May 2014)

I've read a lot good and bad things about the movie recently, so I decided to go to my local blockbuster video and get a copy and watch it to finally understand what all the mess is about.
I've been interested in this kind of genre since I can remember and thus have seen most movies/series depicting realistic space-action (to name a few of my favourites: 2001 Odyssey in Space, Battlestar Galactica, Event Horizon ...). So my expectations were pretty high.
I was positively surprised by the realism of the general space-environment. In contrast to other similar movies there is - as expected - no sound in space except all the sound coming from/through the space suits of the two characters, giving it a nice feeling. Who ever played the Dead Space Series - especially DS 2, will surely know what feeling I'm talking about.
WARNING, HERE BE SPOILERS!
There is one major thing that bugs me: When Ryan get caught in the ropes of the ISS landing module and catches the security rope with Matt hanging on it, why is he still being pulled away? There is supposed to be no gravity and no pressure, so given she caught the rope and stopped his momentum, he should stop moving. But he doesn't, as if he were pulled away from her. Now I've watched the whole movie with my girlfriend and we've discussed this scene and at first we thought it was the earths gravity, but as some later scenes revealed, Matt wasn't pulled away vertically to earth, but rather tangentially. So this whole scene simply makes no sense.
An what's the deal with Matt so apathetically accepting his death? He didn't show any little bit of emotion throughout all of the movie. And why the heck did he keep talking to Ryan and encouraging her to talk to him while her oxygen was running low? Talking uses a lot more oxygen than simply keeping silent. If HE didn't know, shouldn't SHE know, as a medic? I know, I know, if both of them wouldn't talk for all that time, the movie would have been even worse, but that's not well thought-out. Some of you might say he did so to calm her down, but the fact of oxygen running low faster with bow talking could have at the very least mentioned by one of the two.
I also found it quite fascinating that Ryan, as for someone with virtually no experience with landing-modules, had practically no difficulty in operating a Russian and Chinese device. Except the one time where she choose which button to press by "eeny, meeny, miny, moe".
Sadly, Matt had virtually no character: He was emotionless and showed no character development throughout the movie. Actually, he barely showed any character, at all. As to Ryan: Yes, well, she lost her daughter in a totally unrelated event and at first had no problem simply dying, until a hallucination told her not to. Isn't the NASA running strict psychological test in order to make sure psychically unstable or weak people like Ryan wouldn't get enlisted into a mission like this because they could endanger the crew and the mission? Not to speak about her disobedience in the beginning of the movie.
Sadly, most of the movie is not much more than Clooney and Bullock floating in space and trying to get hold of something, so the plot mostly consist of the latter on one hand and some chit-chat to calm Ryan down on the other. Though I have to admit, the (short) action scenes are pretty good.
When rating movies, I usually give every movie 5/10 from the start and then add or subtract points. I've decided to give the movie a 4/10 because: + the effects were pretty decent + realistic depiction of the space environment (with one exception) - Clooneys wooden and emotionless acting (I know, it's arguable) - irrational and non-credible behaviour - very little plot-relevant content