I liked that bit as well (also that he is only refering to protestant theology and no catholic after the reformation, mentioning Harnack in particular.)
No, the Bible is of course composed. (We cannot go back before modernity means that as well)

The fact that the holy spirit guided the composers, is a different matter. But part of the reason, why your theology degree is so long in Germany is because you are supposed to learn greek and hebrew, and you have to look at the different levels of textual formation of the scripture (words that don't fit, events that don't make sense). There is Q, which is a source for Matthew and Luke.

No, the Bible only works as a composition. Anybody that thinks differently should look at what is really there. (and that includes original fragments and transcripts, translations and soforth)