I don't believe that out of the single-digit percentage of planets yet discovered that are categorized as "Earth-like", that any of them fall particularly close on the parameters relevant to "humans would be comfortable living here if they brought the right flora and fauna with them Spore-style").

By special, when speaking about fundamental physics, I certainly don't mean "is capable of maintaining carbon-based life". Earth may be unique in this respect while the physical laws being the same everywhere.

As to the regularity of the universe -- well, that's what the notion of a variable constant of gravity was about. I've seen conjecture that 'dark matter'/'dark energy' might be nothing more than our failure to recognize that the gravitational constant changes in some regions of space.

Even if this were true, so what? Instead of standard Einstein equations one would get a modified set of equations with a new dynamical field instead of constant G. This wouldn't challenge regularity of the universe.

Suffice it to say that I was being 'colorful' in saying that we have no way of knowing that the universe doesn't just stop at the edge of the Earth's lightcone. (It's actually a pretty mundane assertion; most discussions on the matter I've ever heard of make this the null hypothesis.)

The null hypothesis is what? That the universe stops just there, or that we have no way of knowing?

It seems strange. If you walk along an unknown road and are forced to return at one point, do you (without additional information) suppose that the road ends just beyond the last corner you have seen?

By the way, the relevant Earth's lightcone is precisely your lightcone or mine?