You're missing the point. The part you are taking from it is the meaningless point. That doesn't stand on it's own. The idea is that Leia is supposed to be Yoda's ace in the hole, that she is the back up plan. If Luke believes she will die, from Yoda's delivery you get the impression that he just wants him to ignore that even if it's true. I was always under the belief that Yoda knew it was true she would die and is giving Luke the run around. Thus, from the delivery of the lines, Yoda goes from saying let her die, finish your training to she is the other hope. It's just a giant circle, like time travel. If he stays and let's her die, then she isn't 'the other'. If he goes, then she is. Get it?

I didn't say that they needed Star Destroyers and TIE fighters were needed. What I was saying that it was established in the Star Wars universe in the films that both of those could be picked up on the radar of the Millenium Falcon. Earlier in the film it was established that a ship that small couldn't have a cloaking device. The Imperial Shuttles are not signifcantly bigger than the MF. Thus, if they could pick the other two ships up on the radar, they should be able to pick up an Imperial Shuttle landing.