I'm just going to address your first point, because it seems very strange to me that you're so hung up about it.

We didn't name the land/soil "earth" after our planet. We named our planet after the land/soil. It's a function of the English language, but also many other languages.

For example, the Japanese term for the planet is "地球" Chikyuu. This is made up of the character "地" Chi, meaning "land/soil/etc", and the character "球" kyuu meaning ball. Literally translated the planet is just named "Dirt Ball".

So why do alternate worlds have the term "earth" meaning land? Again, because that's just the LANGUAGE. We call the element "earth", so in order to impart the same meaning to us, it has to be called "earth". Maybe this is an function of the in-universe translation magic that we often see in these types or stories, or maybe it's just a meta function that the narration of the story has to be told in a language we the readers understand.

If it makes you happier, just imagine that whenever any characters from an isekai say the word "earth" meaning ground, they're actually saying whatever word in their natural language that is. And that word is the same word as their planet, but we as readers just have it translated for us, like the rest of their entire dialogue.