Who knows what they think?

Why does Estraven think the way he does? I mean, from what we have seen, a lot of the Gethenians are very simple, like the mad king who just wants to keep the status quo and wants to remain in power, and fear anything that might threaten his place. Then we have Tibe, who is just a power hungry politician. We also have a lot of the Orgoreyn officials, like Obsle, who are just afraid for their own lives and position and would do anything to save themselves. These characters, as we can see are simple, and they always show what they are thinking and their actions say it all. However, we have Estraven, who is a complex character. Estraven is always very secretive and subtle about everything that he does. He never shows anyone his true motives. Also, his way of communicating with others just seem out of place. If most Gethenians are just like the other ones, then where does Estraven get the idea that his way of communicating was clear. He said that he was being very clear with Genly the time in the palace, but compare to other Gethenians, he is a closed book. Also, I just realized something about Genly. In the book, we always see him so careless about other people's actions and so naive and trusting. I even thought of him as stupid. As I read along, I see that Genly does not fear death, however. He has been in a lot of dangerous positions and situations but he has never thought of death. Like when he was facing the king, or when he was in that burnt village, or when he is at the prison. He came very close to facing death but he never thought about dying or never fears it. I think he actually wants to die, because Genly knows that if his mission does not succeed, he will have to do time jumps again for the next generation. Maybe he doesn't want to live longer than other people. Maybe he doesn't want to time jump, so he just wants to die. He knows how lonely it is in space now, so maybe he does not want to go back to space, so he is probing Gethen at every place, not caring if he died or not. Estraven just plots way too much and he is out of place in his own world and Genly just seems too indifferent, how could these two work together to bring up an alliance?