Hi all. I see this was answered below, but I had the same issue. Hunted down the answer (should have looked here first, doh!). Figured I'd make the answer more obvious.
If you can't see key frames, or the animation doesn't show up in the graph editor, try selecting the specific node that you are animating. Notice that Kent has the Mapping Node selected (outlined in white) while he is setting key frames. Click away from the node, key frames and graphs disappears. Click on it, they come back. Hope this helps!
Separately: In the compositor, I would have expected the eclipse mask to be plugged into the top image-port. Thinking they read top to bottom. This was not the case. Do ports read bottom to top?
Eric
Eric: Kent mostly answers the overlay question in the next video.
Eric: Thanks Eric!
Yeah this is something I juggled with a bit too!
I didn't know that the key-frames were specific to the node selected!
Much panic.
(Cups have colors, cup is node. Be sure to shove your key-frames under the right cup!)