Lazy Atheism?

[Belacqua]

But the fact that many Christians are not literalists just opens an entire set of problems on it's own.

Yes, everything needs to be discussed, debated, worked out. There won't be a final conclusion about each and every sentence.

There is no instruction manual of which parts of the Bible should be taken literally, and which parts are metaphor, poetry, fable, etc.

Well, there have been many many books written over the years addressing that question. It's true there is no single instruction manual which all Christians agree on. 

As you know, the Bible is a collection of many texts written over centuries, by people with different goals, writing styles, and literary genres. To do a good job on it, a person has to research the background and use his brain.

And, it seems that many Christians, the non-literalists, have been dragged by modernity, to believe less and less of the Bible should be taken literally, because they know (consciously or unconsciously) how ridiculous most of it actually sounds. While the fact is, they would all have been considered heretics, the further back in the history of Christianity we go. Many of them might have been burned at the stake. 

I think it's not true to say that in the beginning, every part of the Bible was taken literally, and then as science proves a literal interpretation is impossible, they switch over to different readings. 

Both Jesus and Paul interpret stories from the Hebrew Bible as allegory. That's pretty far before modernity, and they weren't dragged to it. 

St. Augustine (354 – 430) also said that if a literal reading contradicts what experts say about the world, then Christians shouldn't stick to a literal reading. I don't know which parts he had in mind, but for example there's a place in the NT where Jesus goes up a mountain and can see the whole world. Augustine knew the world was round and that no such mountain exists. I also don't know enough about Greek idioms, but I know that in (for example) French, "tout le monde" almost never refers to all the world. "Tout le monde sait que le restaurant est trop cher" refers to all the people who happen to know about a particular restaurant. 

So literary usage, and language itself, is full of non-literal expression. As I say, a reader has to use his brain and do his best. 

In the Song of Songs, when the lover says "You have dove’s eyes behind your veil" that was not intended to be literal. That would be monstrous.

Also I expect you know about the Pardes system. This was in use from medieval times, and was not an attempt to save as metaphor the things that science had shown to be impossible. In this system, each and every verse is already literal, allegorical, comparative, and esoteric. There are Christian versions of this, also. 

Augustine worked hard on this issue. But we have to keep in mind that he used the word "literal" to mean "what the original author intended." So if the original author intended a sentence to be metaphorical, then the literal meaning is metaphorical. (The idea, of course, is that with sacred scripture the original author may not himself have known the deepest meaning of what he was writing.)

And all the while, this god, is viewing the entire situation, knowing that a very high percentage of his followers are getting it wrong. Are some of them, despite being devout believers, getting it so wrong, that they are as destined for hell as any non-believer? I'm sure there are many Christians that believe so.

Yes, if we think of it as a quiz, it doesn't seem fair to me. If each individual really has to get precisely the correct hermeneutic in order to go to heaven, that's too difficult. 

Before Luther, the Bible was often approached the way we would look at the books of legal code in a lawyer's office. Interpretation is difficult, and people who try to do it themselves are likely to end up as hopelessly lost pro se defendants or Sovereign Citizen oddballs. It's better to hire professional help. 

So if you or anyone doesn't want to take the time to work out skillful interpretation, I don't see that as a problem. We can all live long happy lives knowing nothing about it. As with all subjects, though, if we start passing judgment it's probably better to know a lot. And this applies to religious and non-religious alike.