Very nice discussions/descriptions, but I've got 2 concerns.

Pamela said that Dark energy is trying to 'push' the Andromeda galaxy away from us at 58 odd km/s, while gravity 'pulls' us together at about 359 km/s, giving a resultant of some 301 km/s. I believe it will be the same if there was no Dark energy. The pure kinematical expansion rate (the 'momentum like' expansion) that slows down over time would do exactly the same thing without Dark energy.

On light orbiting a black hole, Pamela said that light can orbit at half the Schwarzschild radius. Isn't that rather at 1.5 times the Schwarzschild radius (r = 1.5Rs = 3GM/c^2)?