Earlier quoted context omitted.
Honest question: how much of the torrent content is corrupted in some way? I dabbled with file sharing back when Kazaa was a thing and I infected my computer to the point I had to reinstall the operating system and I "learned my lesson." But maybe I overlearned the lesson, and it can be used reliably?
Kazaaa has nothing to do with torrents, but what do you mean by corrupted? Torrenting can cause a fragmenting issue, but defragging clears that up. And like anywhere else, random executables sometimes contain malware but there's nothing inherent in torrents that makes that more likely.
It can, but the clients I use(d) had an option like 'preallocate space', or similar. Then it doesn't, at least not as much.