Unfortunately this is not planned at the moment :(

I think it's more pegi7 than pegi3. Maybe not all discipline for 5 year olds can be okay.

The more expensive one is the German (game language) version for Germany (USK), this one is the "international" German language version (PEGI), which also includes subtitles in German, French, Italian and English.

Yes.

All Nintendo's games use the language set on the game console. If you switch the language there, the language ingame should then be switched too.

yes it is possible. you have to do the purchase procedure and put the mode "withdrawal in shop".