It's inherent to the math that defines the entire concept of a black hole, or "spacetime" in general. So to the extent we can contemplate the question at all, we can be pretty confident that creating black holes is Very Hard.

There's a lot we don't know, but the fact that the universe is consistent means it has to be consistent with what we do know already. Don't be so openminded your brain falls out.

> the fact that the universe is consistent

We don't know this either.

We are very limited in detection. Our energies are small.

How "standard" are standard candles and other references? Are the facts that stand as the basis for our theories even correct?

We are too primitive to be dealing in absolutes.