In my answer to you last week, I took a "let's assume you're right" approach and we wound up logically stuck with intelligent design as the most rational description of how nature works. That left us with an intelligent designer as the best explanation of why nature works that way.
 
This week, I want to address your overarching question which I think can be summed up as "How can one rationally defend the view that scientific consensus is questionable while religious doctrine is certain, especially in light of the contradictory claims of each religion?"
 
Your question is based on a common opinion people have, namely that science is based on reason while religion is based on faith which is irrational. There's truth to that but it's too categoric. For example, philosophy, mathematics and science all base their logic on axioms, which are essentially assumptions that have to be taken on faith. These axioms include such ideas as: Logic will disclose truth; our perceptions correspond to objective reality; and that all phenomena have prior causes.
 
We accept these axioms, even though we know that sometimes logic leads to absurdities, not truth, that our perceptions may be inaccurate, and that some phenomena may have simultaneous or even subsequent causes, or no cause at all, for example in quantum systems.
 
On the other hand, religion has plenty of reasonable things going for it, including imperatives like don't kill or steal, love your neighbor, and give charity.
 
You mention that religions with mutually exclusive claims can't all be divinely correct, unless G-d likes to contradict Him/Herself, and that's a good question. Let's take a closer look at that.
 
A key factor distinguishing Judaism from other religions is the Sinai Experience. Other major religions have a single prophet with a few witnesses to back them up, followed by a lot of prosletyzing. Judaism's different. We've got a public divine revelation to millions of people followed by a precise and unbroken chain of tradition from then until now.  
 
"But whoa!" the rational man protests. How do we know it really happened? There are plenty of possible explanations as to how that story came about. But are there really? Let's look a little closer. We can all probably agree that some long time ago, a nation of Hebrews left Egypt somehow. We can further agree that some time later they made it to what is now the Land of Israel. Where it gets tricky is figuring out what happened in between.
 
In what seems to us like the foggy past, the ancient Israelites ostensibly left Egypt without a Torah and arrived in Israel with one. Obviously they picked it up somewhere along the way, but where and how? What are the alternatives?
 
We could do a study. Ask ten random people on the street what happened at Sinai and you just might get ten random opinions (especially if you ask Jews!), ranging from "Nothing. They made it all up." to "Exactly as it says in the Bible." and everything in between. For instance.
 
Ø      Aliens redeemed, then indoctrinated, the people at Sinai.
Ø      Moses conned the public into believing G-d spoke to him.
Ø      He was a mass hypnotist.
Ø      The people were enlightened and composed the story as literature.
Ø      The Israelites made up the story to justify Zionism.
Ø      We can't know because the original story got distorted over time.
Ø      There may have been an unverifiable personal revelation to Moses only.
Ø      There may have been a mass revelation but its content is unknown to us today.
 
Whoa fellas! You can't all be right! Let's go about this rationally. We could treat each claim as a kind of hypothesis. We can't test history experimentally, but we can explore each option's relative feasibility.
 
I went through exactly such an exercise about 26 years ago and realized that all the alternative hypotheses to the Torah's account are faulty. I have no evidence of alien interventions nor any tradition with a narrative about aliens. Nor have I any precedent for a mass hypnosis of such magnitude. Besides, who would Moses hypnotize? A people who argued about everything including what to eat, where to go, who to lead them, intermarriage, rituals and nepotism? Nnnaw, I don't think so.
 
Moreover the revelation wasn't just to Moses. It was public. With all the dirty laundry and dissenting opinion in the Torah, wouldn't it make sense that some alternative history should have trickled through? But that has not been the case. Whoever has a story, has this one. And it stands to reason. Would you be able to re-engineer a whole public's perception about an event they observed themselves? Not too likely. 
 
But what about broken telephone? Even if there were a Divine revelation at Sinai, surely after 3,000-odd years, the details would have gotten muddled? Well, the Torah itself isn't muddled, that's for sure. No matter where or when a Torah scroll has been written, it's letter perfect. Well, you could say that one of the 304,000-odd letters could be written as an 'aleph' or a 'heh', and therefore the text is variable, but I don't think that 99.9997 per cent precision over 3,321 years and thousands of lines of transmission constitutes 'broken telephone.'
 
And the oral Torah is just as well preserved. For instance, the biblical mandate for the holiday of sukkot includes to "take the fruit of a beautiful tree." Now I like apples, you may like coconuts, and a third may like grapefruit. Who is to say what's beautiful in trees. And yet, whoever has a tradition of any type has the tradition to use a Mediterranean citron, or esrog. The same precision applies to the oral tradition regarding all 613 commandments of the written Torah.
 
I guess when the call is important enough, you make sure the phone doesn't break.
 
When a scientist wants to verify an event, she looks for many observers and the more, the better. And she won't want clones -  rather observers should be independent and diverse. And the more numerous and diverse the witnesses and the more precisely all stories match, the more trustworthy the observation is, in objective scientific terms.
 
According to these criteria, it may well be argued that the revelation at Sinai is at least as well substantiated as any historical event on record! Bahhh, the skeptic may say, but so what? May one change the rules of evidence in the middle of the game of knowledge? If these are the criteria of empiricism, then who cares if the object of that knowledge is something weird and wonderful, or even Divine?
 
On the contrary, to marginalize or trivialize the Torah's claim to divine origin without any rational evaluation of the evidence, would be absolutely anti-scientific, and arguably even less rational than accepting it as true.
 
Throughout the late 1700's the French Academy of Science adopted the view that meteorites cannot exist and all such collections were discarded in embarrassment. At that time, Antoine Lavoisier, the father of modern chemistry adamantly ascertained, "Rocks cannot fall from the sky because there are no rocks in the sky." Then on the night of April 26, 1803, two thousand meteorites thunderously pummeled the French countryside flattening that paradigm in a hurry.
 
For some men of science, it may take nothing less than a gigantic divine intervention, like the coming of Moshiach, to awaken them to the rational plausibility of the tradition from Sinai consisting of something more than a bunch of rabbis twiddling their thumbs trying to memorize the ten commandments.
 
What about you, Robert?