Questions about anime in general are allowed, and encouraged. We don't need in-universe questions only.
Look at the FAQ for example:
Anime and Manga - Stack Exchange is a Q&A site for enthusiastic anime
and manga fans. This includes questions about:
- Plot, character, or setting explanations
- Historical or societal context of an anime or manga
- Anime and manga identification
- Franchise/series reading or viewing order
- Anime and manga production
- Tropes, terminology and other general anime and manga related information.
Not all of these are directly on specific anime.
The second example you gave is a list question, we've had a chat discussion over it and defined rules about questions whose answer is a list. You can read it here: What is the status of list questions on this site?