Disintegrating as you enter a large black hole, instead of experiencing what's inside?

kshetline wrote: My amateur interpretation of the first two items is that as you fall into the black hole, in your own frame of reference, the universe you leave behind will rapidly age from your perspective.

This is wrong, that happens when you hover at the horizon. If you fall in with the negative escape velocity the kinematic time dilation will cancel out the gravitational time dilation (therefore $g^{tt}$ in raindrop coordinates is exactly $1$) and only the Doppler redshift will remain, so you will see the outside behind you redshifted, not blueshifted. Right in front of you the blueshift would be infinite, but since the black hole in front of you is black, that doesn't help you seeing the infinite future of the universe.

Let's say a mirror hovers very close to the event horizon and laser pulse is bounced off of that mirror, shot from above.

Now we know that it takes a very long time for the pulse to return back up to where the laser gun is, because we have been told so by black hole experts. It's called Shapiro delay.

The pulse spends most of that time on the return leg. The down hill part of the trip is quick.

At least if we use Gullstrand–Painlevé coordinates the above is true.

https://en.wikipedia.org/wiki/Gullstrand%E2%80%93Painlev%C3%A9_coordinates

As using Gullstrand–Painlevé coordinates eliminates OP's trouble of reconciling things that black experts have said, Gullstrand–Painlevé coordinates seem to be the right coordinates for us to use.

Points 1, 2 and 3 are correct, but the rest of your post isn't.

An observer falling into a black hole does not see infinitely into the future when looking back. There is only a finite time available for signals sent from well beyond the horizon to reach the falling observer before they cross the event horizon or shortly afterwards, intercept the singularity.

This is tricky to see in ill-behaved Schwarzschild coordinates - both observer and light signal asymptotically approach the horizon, but the light always catches the observer in a finite time - but much easier to visualise in other coordinate systems.

You can find a full discussion and answers giving the full derivation of just how far into the future the falling observer can see (not very far at all) at Does someone falling into a black hole see the end of the universe?

In comments you claim you are not asking about what the observer can "see", in which case I fear you are venturing into metaphysics. There is no agreement on time between different observers and no observer measures THE time. About as close as you can get is to put a transmitter a long way from the black hole, which pulses every second. The gaps between those pulses will seem longer for the falling observer, but not infinitely long, and the observer will receive a finite number of pulses before being annihilated at the singularity.

Therefore "... in your own frame of reference, the universe you leave behind will rapidly age from your perspective" and "Once you cross the event horizon, all you once knew will essentially be infinitely in the past" aren't true.