I would say:
1) To resign and abandon are not the same thing. The first one means that you have convinced yourself about something and you accept it. To abandon really means giving up, either convinced or not. The difference can be subtle, but to resign would mean that you have understood the fact that you have little chance to be saved and have accepted it, thus you have resigned yourself. If you wanted to use "abandoned", i guess it should have been "As there is little hope of being rescued, I have abandoned the idea of being rescued".
2) This one lacks context. In my point of view implies that it is what you think, while in view takes consideration of past events. Like in view to the crisis, this plan will not work. Both could work depending on the situation I believe.
3) Attitude and mentality are not the same thing (once again). One's attitude has to do with his/her behaviour. So it is something that usually shows physically. Like being rude, or being mean. The mentality is more related to how a person thinks and it shows more in the choices they make. If someone has a bad mentality, this person will usually do bad things. This means that you could have someone with a good mentality but with a bad attitude. Attitude is often used when speaking about the way someone interacts with someone or something so I would guess the correct answer here is "attitude".
Little note, I am not a native speaker so I may be wrong! This is how I would answer these questions. If my answers don't make sense, please by any means, correct me :)