1) I think that English and Spanish would be included as school subjects because a lot of people speak them around the world. The other languages: Japanese, Esperanto, Arabic and Latin aren’t as useful as they are.
2) I think that any language may disappear because they are very important for the culture of a country, for this reason governments may protect them and promote their use at the school and at the media.
3) In Spain there are three languages: Catalan, Basque and Galician.
The government gives subventions to the publications in Catalan and it’s necessary to speak it to work for the Administration. The government must protect and promote them because they are official languages.