How does bilingual education fit into minority language maintenance, language decline and language revival?

There are important dualisms and paradoxes throughout the study of
bilingualism and multilingualism: for example, the individual bilingual
person as different from groups and societies where bilinguals live; the
linguistic view compared with the sociocultural and socio-political view;
language skills and language competences; codeswitching and
translanguaging. The opening chapters (1 to 8) present foundational
issues that precede and influence discussions about bilingual education.
Before we can sensibly talk about bilingual education, we need to tackle
questions such as:

Who are bilinguals and multilinguals?

How does bilingual education fit into minority language maintenance,
language decline and language revival?

How does a child become bilingual or trilingual?

What effect does the home and the neighborhood play in developing
bilingualism and multilingualism?

Does bilingualism have a positive or negative effect on thinking?

What do we know about bilingualism in the brain?