Are most of JS Bachs works for education?

Answer 1

No, but a large majority of them are. Chopin perhaps is probably the only one that trumps Bach. You must understand that while Bach did serve under the patronage system (plainly put: a musical slave), he also composed greatly for his huge family to both teach and improve their musical talents such as the Little Organ book for Wilhelm Friedman Bach or the Notebook for Anna Magdalena Bach (second wife) presented to Magdalena.

Arguably his most profound contribution to music: the Well Tempered Clavier volumes 1 and 2 were composed to show the benefit of equally tempered keys more than to show virtuosic talent (for which he was already renknowned for). Having spent the last portion of his life at a post in Leipzig as the Director of Music for Thomasschule school, he dealt with students and composed for them.

This is just one of the reasons why Bach's music is so technically difficult to play.