Originally Posted by ModelPerfect

Being as they were all malnourished when they cracked open the ship, I think it can be assumed they had insufficient supplies. It's unlikely that those supplies increased on their own, so if he had "rescued" all of the prawns, he would have doomed them all to a starving death, which is why he was flying home alone to bring back help...for them and for the human who he previously promised to help. Not to mention he didn't exactly have the resources to move all the prawns and try to secure supplies while constantly under fire by the humans.

The questions that jumped out at me were:

(1) Why isn't the pressure needed to suspend a ship that size and that height crushing everything underneath it?
(2) If the ship was out of fuel and they needed to fly up to it, how did they remotely get it to move over the pilot ship without any physical contact at all to transfer the fuel?
(3) Just where are they going that they can be there and back in just 3 years? The next closest star would take 4 years even at the speed of light!

Those questions could be explained by technological advancements that defy our limited understanding of Physics, but leaving open questions like that distracts from the movie imho, although I did thoroughly enjoy it.