Guess I need some videos.
Perhaps chain wasn't a good word. Combo? Dgrab>(possibly) Dgrab>dair>dgrab>(possibly) dair or nair or bair.
Idk, I'm thinking off the top of my head from my last games with a really good Falco I've played.
As far as ledgecamping is concerned... ROB obviously can't hurt Falco from that position but that isn't the point. You ledgecamp if you're winning, when you don't have to do anything to him. This puts Falco in a tough position because it forces him to the ledge, off-stage even, to get ROB off it, which has obvious repercussions. ROB cannot ledgecamp if he's behind but it's a great way for ROB to potentially widen a lead he does hold, since it's a positional advantage if Falco has to come to him.
But yeah, I'm not getting into this again. -_-
That's "if" he goes. Without a time limit, a Falco can simply stay on the stage as long as he wants to. They always say patience is a virtue.
And more than likely, you'll screw up before he does giving him a chance to knock you out.
It's not really that unsafe high in the air against Falco, he has poor lateral mobility and falls too quickly to really take advantage of ROB's blind spot.
It's not like a good Falco is gonna actually jump up there with you. -_-
You gotta come down sometime and he'll be prepared for that. If anything else, he can just chillout till you land and continue is rain of lasers.
If you try to go in for an attack, there are many options he can take. If you're good at spacing, you might be able to get him off your feet for awhile, but don't expect it to last long.