Well I guess you have selective reading skills.

If you download the manual in the bottom sticky. It will explain may of your questions.

If you receive a corrupted file msg., that means something is wrong with the file. Whether it will play correctly are not if you finish the d/l, who knows. That is a choice and chance you have to take.

Your last question goes back to the first answer I made in this thread. The more hosts available for the d/l create the swarming effect by pulling pieces of the file you are d/l from the different hosts you are connected to. A single host does not provide the entire file, but it comes from multiple hosts --- thus the swarming effect.