No a duvet cover.

Thanks. I tried translating it in my language to English, and I also got dust cover, but I thought it was a mistranslation.I thought a dust cover was the thing some people put on their bed during the day to prevent dust.

This, I could not find an image of, but it's the thing she wraps around the blanket. (The same video, but you don't have to visit YouTube https://files.catbox.moe/%2F70g75k.mp4)

I sometimes sleep with the thing you put around a blanket (I'm not sure what the right word for it is in English)

1970

If you use something like Jackett or Prowlarr, no. If you use the web interface, yes, but they don't verify the email you enter, so you can just type in a random one.