What Do Orthodox People Really Believe?

XGH has claimed that several rabbis have admitted to him in private beliefs that they would never own up to in public. I wonder, if that's true, how many other rabbis are the same way? And how many of the rank-and-file Orthodox are as well?

There are several claims which are (in my opinion) transparently false but Orthodox Judaism depends on. For example:

1. 600,000 Jews literally walked out of Egypt at one time, plus "a mixed multitude" who went with them, along with flocks and herds and "very much" cattle.
2. There was a global flood that killed all living things except those which lived peacefully together on a man-made ark for forty days and forty nights.
3. The five books of Moses were written primarily by Moses, plus or minus a few letters here and there and maybe the last eight sentences.

I know that a lot of Orthodox Jews simply assume that these claims are true. I'm sure that some others are convinced by apologetics that they are true. What of the rest, though? Are we to believe that your average, relatively intellectual Modern Orthodox Jew believes these things? Or do they disbelieve, but keep quiet?

I don't really want to call anyone out, but do people like Chana and Ezzie believe that those things are true? Or do they just not think about them? Or do they accept the apologetics without thinking about those? Or are they literally in psychological denial? What about the rabbis? Is it all a big lie to them, albeit with good intentions, like telling children that the ghost of Elijah drinks from the cup at the seder or that the tooth fairy gives you money for teeth?

I'd really love to know. It's a shame there's no way to find out, short of kidnapping a bunch of rabbis and other Orthodox Jews and submitting them to a carefully-constructed polygraph test.