If a black hole is space/time imploding in slow motion what happens when it's done?

Fuck you.

Well, it has to be denser than a neutron star because those still have neutrons.
That's basically the definition. In a neutron star the protons and electrons have merged to form neutrons due to the gravitational pressure, but it lacked the mass to collapse further.

Oh, and the apparent horizon must be located outside the object.

"Interstellar" got the appearance of a BH right. Thorne was a consultant and the CGI artists implemented the equations he gave them. (In fact they did such a good job that professional Relativatists now use their software as an aid to visualization.)

Thorne also told the director that certain key plot-points were impossible. Escaping once you'd fallen through the event horizon. Traveling back in time. The director went ahead with that crap anyway. I suppose we're lucky whenever Hollywood pays even a LITTLE attention to science.

I have worse news for you.
Light has mass.
It travels a curved path (a null-geodesic) in a gravity field.
It has momentum and energy -- and you can't have either of those without mass.
What light DOESN'T have is rest-mass. Because it's never at rest.

That's a good thing, OP.

>It has momentum and energy -- and you can't have either of those without mass.
Of course you can! You never hear modern scientists talking about rest mass vs. relativistic mass, they just use the term "mass", meaning rest mass.

>It travels a curved path (a null-geodesic) in a gravity field.
That doesn't mean it has mass, that just means it travels through space.
Also, momentum can exist without mass.

I think it is okay.

What physicists do you know?
Any will tell you light has mass. Because they lack rest-mass, it's usually unnecessary to add the word "relativistic". It's the ONLY mass they have, so no qualifier is needed. You may be arguing semantics.

Light has energy. E=Mc^2
Light has momentum. Light exerts pressure. Look up "solar sails" or "laser driven sails"
It exerts pressure because it's absorbed by surfaces or reflected (in which case you get double the pressure because the total dV was 2c)

Look, you're aware that the center of mass of a closed, isolated system cannot be moved? No arrangement of gears and whirling weights can change its net linear momentum. (Which doesn't prevent people from trying to build propulsion systems which work in a vacuum but which aren't rockets.)
Imagine a box with a flashlight inside it at one end. Turn the light on and the recoil starts the box moving. The motion continues until the photons slam into the other end and are absorbed. The box is again at rest, but it has moved. That's impossible unless some mass has moved in the other direction so as to keep the center-of-mass in the same position. During the time the photons are in transit, they are the ONLY things moving in the right direction. Therefore, they have mass. This thought-experiment is one of the easiest ways to derive E=Mc^2