You're argument has one major flaw: that's not how science works. Science includes the process of hypothesis and experimentation that gives a result. Proving something supernatural exists does not mean science is wrong, just that there was something science didn't account for, and with that, more hypothesis and experimentation. The science that you talk about is merely the book keeping of what our current conclusions are. The conclusions are in fact always open to change as that's what science invites.
So one kind of supernatural thing exists, hypothesis and experimentation can still happen for new book keeping. And while it opens up the possibility of more supernatural phenomena, it doesn't prove it because their is no evidence to connect it. Hell, even if all supernatural things are real, science is never wrong, just the book keeping is different.
I disagree with the crank example in real life...or specifically the assertion about fossils being planted to test faith...most educated creationists don't take that seriously. There probably are some more foolish ones who do, though.
Fly High, Seek Peace
Regarding the real life examples - in particular the heading comment "To be fair, the scientific consensus is that there are plenty of aliens, they're just really far away. "
This comes down to the idea that there is no reason to assume that whatever situation caused life to occur here couldn't happen elsewhere, and given the utter vastness of the universe - it is likely that it has (and does) happen elsewhere in the universe. However the massive size of the universe makes interstellar travel impractical for any civilization which is not very long lived (unless someone finds a way around that pesky speed limit of light speed) and very patient. It takes light several years to get here from the closest stars, most stars are thousands (or millions, or more) of light years away.
The question then becomes - how common is life in the universe, how common is sentient life, and why haven't we seen any evidence of them yet? the Drake equation makes an attempt to guess at the first two (though given the vastness of the universe, just about any set of non-zero probabilities will make for some life - and if any of them were zero - then we wouldn't exist either.) The latter question is known as the Fermi paradox.
Of course, there is the matter of theoretical vs experimental. Many things can exist in theory which haven't been experimentally validated yet - and yet still hold theoretical viability - atomic theory greatly predates experiments demonstrating the nature of atoms, black holes are commonly assumed to exist even though evidence for them as yet remains rather thin, and the scientific hypothesis regarding the origins of life (collectively known as abiogenisis - evolution is about how living organisms change rather than start) has never as yet been fully reproduced in a lab (though there have been some tests which sort of poke at it creating what we think are similar compounds to what existed on ancient earth).
So on a practical note we haven't seen any actual evidence of aliens existing, but the general consensus is that there is no reason it couldn't exist elsewhere in the universe, and the idea that we are totally unique in the vastness of the universe is probably less likely than life having developed elsewhere.
I disagree with this: