Recovering low is great advice. When trying to gimp, especially at higher percentages , Falco's sideB does meteor, which is something to watch out for. I think Falco's reflector is being a little overrated. Compared to Fox and Wolf, it's not great.
Falco's vertical recovery is really weak, as was mentioned earlier. As long as he can't phantasm, Lucas is in a very good position.
Does anyone know if Lucas's fair stops phantasm? I know that aerial priority is weird.
And iirc as long as you don't jump immediately after being cged off the stage, the cg->spike combo will miss.
Approaching is probably going to be the hardest thing in this match-up. Lucas has pretty good airspeed, and extended aerial hitboxes, which helps a lot, not to mention projectiles. If a Falco is shdl'ing, they're probably not worrying to much about reflector.
All I can think of at the moment...