Einstein on Pokemon

and we have become exceedingly efficient at it.

No it's not. It has no beginning or end

That's debatable

Do we have substantial evidence to support or deny either conclusion?

We know it has a begging.
So unless the universe is a sphere, it has an end which is simply yet to be determined.

beginning*

But is it contained in something? If it ends, then what's beyond the ending? Is that infinite? Is the nothingness at the edge of the universe infinite?

neither does an apple. apples are now infinite.

the end is undefined, the start of it however has been methematicly determined

But what came before the universe? Was there another universe before ours that collapsed and returned as "ours"? Are we expanding inside another universe? The beginning has yet to be found I would say.

Hypothetically, think of it like this.
A shoebox.
with marbles in it.
They start off in any given place in the box,
so if you shake the box they must return there at some point, because it is one of the possibilities given by the box.
Now the universe can be this box as well, at some point it will return to the state it was once in...another big bang, so the universe resets itself every
*ahem*
10^10^10^10^10^1 years, or so.

personal theory, massive black hole, swallowed everything, collapsing on its own as it began to exist once by the collapse of a star, and thus it explodes, creating a new big bang and so on and so on

The only problem is it's so hard to raise Zubat if you catch one in Mt. Moon... their pre-evolution stats are balls. Crobat is the shit though.