The gravastar article does not claim that black holes do not exist. It just claims that there is another kind of body that has pretty much the same properties of a black hole from the perspective of a distant observer.
From your discussion above I surmize that you do not realize that space itself is sucked into the black hole such that space is traveling at the speed of light at the event horizon. That is why light cannot escape. Massive particles could be accelerated by the gravity of the black hole up to speeds close to the speed of light. So from the perspective of a distant observer, such particles would be traveling at nearly twice the speed of light at the event horizon. Of course, the distant observer could not actually observe such particles for at some distance outside of the event horizon, the particles would have attained the speed of light in the frame of the distant observer, and it could no longer be observed.
But mathematically we can calculate the speed of space and any particles in that space as they get sucked into the black hole. We know the boundary condition for when the space hits the singularity (which BTW is not a singularity-see below). Since the singularity is stationary in the frame of the distant observer, space cannot speed into faster than the speed of light. Therfore, massive particles can at most crash into the singularity at twice the speed of light.
Black holes only have a singularity in general relativity bnecause that theory breaks down at Planck scales. We need M-theory to calculate what the singularity actually looks like. It looks like either a spherical or cylindrically symmetric membrane across which a phase transformation occurs from an outside space containing fermions to an inner space containing only bosons. The bosons are what is usually called the unified field. It is from this space that Lee Smolin postulates that new universes are born. Greene's book "The Elegant Universe" gives an outline of the birthing mechanisms. The outer space is most likely a quark plasma. But its possible that there are intermediatory very massive particles at such high energies and perhaps more than one membrane and phase transformation.
My personal view is that the unified field is 26 dimensional. And that the outer space of fermions has 10 enlarged dimensions and 16 compactified dimensions. My guess is that the 10 enlarged dimensions get compactified across the membrane. With 26 dimensions, calculations assuming conservation of phase space show that entire universes can be packaged in tiny singularities.
The paradox that I do not yet understand is that the universe birthing process invloves the creation of new space as well. That is, the resulting universe has more space in it than was ever absorbed by the black hole. Perhaps inflation creates space. Afterall that is how from an energy perspective an entire universe can come from nothing.