I think you are unfairly applying today's standards to the standards of the time of the author. In those days, it appears they defined a "bird" as any animal that flies. There is nothing unreasonable about this. It was only later that man decided to distinguish between birds and mammals. There's nothing wrong with that either, but it certainly doesn't make the earlier designation wrong. It just means that we classify differently today. Who knows how we will classify 100 years from now?
What if Job really did not exist? Does that change what the book of Job has to say?
Absolutely 'Yes'. Since there is no arguable reason to suppose that the story of Job was an allegory or parable, then if it was just made up it would put into question every other teaching of scripture. How would anyone know what to believe? Does your church teach that part or all of the OT is only metaphor, when there is no clear context that it is so?
What if Adam and Eve are only proverbial parents of ours and not real, historical ones? Does that change the message of their transgression, does it make us any less fallen?
It completely changes the message because it never happened! Does God need to lie and invent things that never happened? If God wanted to just explain the nature of our condition at birth why not just do it, as opposed to concocting a false story about it. I believe it matters a great deal whether the stories of the OT are historically true or not. Jesus speaks of Adam for goodness sakes. Was He lying?
Nevertheless, it makes the Bible a source of incorrect information. If every word is the Bible is true, this is incompatible. Clearly, the inerrancy of the Bible is not in every word and dotted i, but in the message it brings forth.
How would anyone know what to believe?
It shows how we should be (like Job) if disaster strikes. Never accuse God, and always trust in Him. It's easy for us to love God when things are going good, but any shake their fists at God for their misfortunes. The story of Job simply tells us that such a thing would be wrong.
Does your church teach that part or all of the OT is only metaphor, when there is no clear context that it is so?
No.
Why would a story of what happens when we transgress and reject God change the nature of our fall, which happens daily -- as we fall repeatedly? What's important in the story of Adam and Eve is that we can recognize ourselves in them, because we repeat their error and "want to be like gods." Adam and Eve exist as "archtypes" of humanity. But excavations show that mankind did not just happen over night, or even in one week.
In Islam, Muhammad simply writes down what Allah dictates to him. That result is the Qur'an which means "reciting" in Arabic.
I am not aware of any Protestants who think of the Bible in this manner, no matter their high regard for scripture. But perhaps some Protestants do regard the Bible in this way. I doubt seriously that any Catholic or Orthodox thinks of the Bible as a "reciting".
But is that how Calvinists think of the Bible? God simply dictates to people who then just record the dictation word for word, like a good secretary?