Thanks chok, it's always helpful to hear another person's perspective. I never really thought about angle of approach; watching the videos again, he consistently got around my b-air by coming in from diagonally/above. I might've been able to counter by positioning myself under the platforms more.
What you said about protecting but threatening is soo true. I even felt some momentum going into game three--he was being more careful because he realized how easily he could lose a stock. At the beginning of that game I had an easier time landing hits, but then I failed to capitalize on them and he started to set the pace again.
I have an instinctive tendency to try to get back towards the middle of the stage after getting shined, even though I know it's better to wait and see what he does. Some Foxes will try to shine -> wavedash -> keep attacking, but ICs get out of stun before he can reach them, so sometimes just waiting after you get shined can lead to a free dash attack or grab.
F-air and f-tilt are both really good in that match-up but I always forget to use them...
On the reverse d-air CG:
D-air has set knockback. Falcon is big enough that d-air will hit him immediately as soon as he's released, regardless of whether you shorthop or fulljump. Also, the shorthop version will work no matter how he DIs, but there's not really any point in learning it because it's easier to fulljump.
Falcons typically escape by SDIing up and jumping out. Most Falcons don't know how to escape/aren't consistent at it, so I haven't really spent any time thinking of DI mix-ups. If a Falcon is consistently escaping that way, maybe you could d-throw -> d-air -> f-smash to catch his second jump?
Alternatively, you can d-throw chaingrab him for a while, but it's slower and harder to do. I guess you could start charging an f-smash halfway through the throw animation to rack up damage faster. And if he's trying to SDI up, he probably won't DI away, which makes the regrab easier. (None of this is really important, though, because most Falcons you meet won't even be able to escape the reverse d-air in the first place.)