I think there's some big problems with using "the earth is round" as an analogy for religious claims. There's lots of evidence that the earth is round and it is quite easy to demonstrate that fact (the shadow of the earth on the moon, boats dipping below the horizon, shadows from poles, pictures/videos from space, etc.), and it would be quite easy to disprove if the earth was actually flat (pictures/videos of a flat earth from space, boats never disappearing, consistent shadows, no time zones, etc.). Your point with this analogy seems to be that just like it is difficult to prove that the earth is round (and that we mostly believe the earth is round without good reason/evidence), it is similarly difficult to prove religious claims. But it is actually very easy to prove/disprove the shape of the earth, so I don't think your analogy is helpful. Actually, it seems to be a serious criticism of religion, since they are unable to prove the truth of their religious claims while so many other claims are terribly easy to prove/disprove.

One point you make that I somewhat agree with is that pointing out a flaw in a religious text doesn't necessarily invalidate the whole religion, just as pointing out a flaw in a scientific paper doesn't invalidate the whole paper. However, if it is the position of that religion that the religious text has absolutely no flaws (which is the case for many people), then pointing out a single flaw in the text would invalidate the religion. The same cannot be said about scientific papers, since they never claim to be perfect.

A smaller point, keep in mind that while there's nothing necessarily wrong with being self-referential, there is something wrong with circular logic.