I disagree. Marth can handle Peach and Jiggs way better than Falcon can. He can also handle spacies way better. Peach/Jiggs can't get in on Marth, while they can style on Falcon pretty badly. And nah, Falcon won't be winning any national's anytime soon.
Your entire argument was invalidated when you said "Peach styles on Falcon." Lol. Falcon is one of Peach's hardest matchups. His speed and ability to kill her on any stage below 100% makes him a nightmare for her. Falcon does ok against JigglyPuff as well. Maybe slightly worse than Marth. Marth v Puff is pretty close to even, if not slightly in Puffs favor.
And yeah, Falcon will win some nationals. Watch the videos of S2J vs M2K from Genesis 2 and NYTE. He is amazing and still makes mistakes. If he could gentleman like SS he would've beat M2K at Genesis 2 (the same M2K that 4 stocked Darkrain). S2J also beat Tope, who has beaten every pro Falcon main at one point or another.
Falcon does fine against spacies. In 2012, pro Falcons can consistently death combo spacies enough to win against them. These are the best in the country for their respective character:
Marth - Taj, Shroomed, Dart, PewPewU, TAI
Falcon - S2J, Hax, Silent Spectre, Darkrain, Scar
I think those Falcon players have a better chance to win a National than the Marth players.
Or wait, do you still think M2K wins all those games with Marth? lol. He uses Sheik dude.