That's a bit ridiculous. No one is ever gonna pay you for that. You get something for free, the video you want to watch, and the deal here is that your unused upload bandwidth gets used to help transfer it to others. It's a social contract thing, and thinking you might get a better deal magically by refusing it won't make that deal appear.
> You're slowing down my connection
In which way? It is using your upload while you download a video. That does not harm you.
> causing me send data to someone I do not know
You never seeded a torrent? You never connected to an internet site you did not know the owner of? It's pretty much the same thing.
> You're going to be liable for anything malicious that gets sent back
Who is the you here? A Peertube instance won't be liable for malicious data, how would that even work anyway. Even if it were possible: The websites spreading malware with their ads were not liable either. This won't happen.
> if you're MitM'ing it to scan it properly, why are you wasting my bandwidth and storage?
Right, that would be a bad idea.