Our Comfortable Black Hole

Are we living inside of a black hole?

As I gather, this is the concept: At the center of a black hole is a singularity. Singularities are thought to be extremely dense and extremely tiny.

But a singularity can explode. One did, nearly 14 billion years ago, and we live in the universe that was created by that event.

So suppose that the singularity at the center of a black hole did explode. Since nothing that moves slower than the speed of light can (in theory) escape a black hole, would the resultant universe be contained inside of the event horizon of the black hole?

If somehow we could slip past the event horizon of a black hole and then return, would we discover that what we thought to be a black hole was instead, another universe? And if we could travel faster than the speed of light and go beyond the edge of our own universe, would we then find ourselves in a much vaster universe?

Or would crossing the event horizon of a black hole, or of our own universe, be a dimensional shift and the size of the new universes that we found ourselves in would seem to be about the same as our own? Is the "final frontier" truly that final?

Would the heat death of the universe, from another viewpoint, be the same as the evaporation of a black hole?*
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* Not that I understand any of the math.