As many others have already said, you are definitely not weird for it. If thats what you enjoy, don’t let others take it from you just because they might consider it weird.

For me personally, I do both. Sometimes I listen to background music while doing other things. As someone said above, its like elevator music. However, for me it improves the mood for some tasks.
On the other hand, I sit down maybe three times a week just for listening to music. I fully follow the emotions and story of a song or album.
The music is quite different between these two modes. For the background music I just need some good tunes. When listening fully, the song must have a text I like or be a really good instrumental song. Then I also need the right song and order of songs depending on mood. Mostly it’s a curated list from which i select song by song. If I hear a great song in background listening I add it to the list. Later I listen to a more songs of the album or artist with full attention and add the ones I enjoy to my list. Funnily there are songs which then have so much meaning for me, I cannot listen to them in background anymore. Either I skip them or i put my full attention to them.

No, the comet stays almosf stationary to the stars during such a short time. Hence, it is in every image and therefore also in the final median image.

For average astrophotography satellite trails are not really a problem as it may seem here. Almost any image is processed in such a way in any case. But there are special projects which are heavily impacted, for example the search for asteroids. There you need to look at each individual image, as fast moving asteroids would be deleted with this method.

If you are interested in (astro)physics, here are two channels which i enjoy and can assure for their correctness on research topics:

Dr. Becky Astrophysicist talking about what’s happening in space from planets currently visible by nakedness eye to new impactfull research papers. She explains everything in an approachable way.

Angela Collier Theoretical physicist, makes long story telling videos about physics and societal topics surrounding research. Most videos are >50 minutes, some are more than three hours. However, they often stray from the original topic.

For some talk about philosophy, I can recommend Philosophy Tube. Most videos are somewhat short of an hour, but explain some philosophical topic in an approachable and interesting manner. Just don’t be detered by her extraordinary costumes for each session. I think she research the philosophical questions quite well.

As always, there is a relevant xkcd: