Hi,
The custom fields of different tables will display in different places.
So it requires different display settings.
The product custom fields can display in a wide variety of views and you want to be able to control them finely.
The address custom fields always display in an address form or an address display. So it doesn't require all these display options.
Same for the translation. There is no point in being able to translate address custom fields. You're not going to ask your customer to translate his address in all the languages of your website. But it make sense to translate a custom product field in the different languages so that the customers can see the value you enter in the custom field in each language properly translated.