As a Falco main, Marth secondary, I'll comment on those 2 characters. I'd like to point out, however, that you guys look better then me, so I'm not sure how applicable what I'm going to say is. Try it though, see if it helps. By the way, I love the 7% to death techchase in the Falcon vs Falco match, at around 2:05 in. That was awesome ^_^
For Falco, I find you don't use your lasers nearly enough. It's Falco's best move for a reason, you know. You can manipulate your opponent like a puppet with them. Sit at a distance and spam SHL, and he has to approach you. Approach with fast, high SHL (still hitting him if he's on the ground, but high enough that you can catch a SH with it), and watch your opponent struggle with his extremely limited options for dealing with it. SHL approach will force most opponents to shield it. From there, start a pillar, grab him, or dash attack through him and get behind him. Falco is a character with whom it's very, very easy to take control of the entire stage. Do so, that's why he's such a good character.
A little thing too, when facing a fastfaller, your combos against him should be waveshine -> shffl drill, waveshine. If that vs Fox match was just to practice your waveshines, then disregard this, but if you were acualy comboing there, I'd suggest you add in the dair. It throws on a significant amount of damage, allowing you to end your combos sooner, which means less of a window to mess up or follow DI incorrectly.
Like I said, Falco is a character who likes control. Of everything. If you aren't close enough to your opponent for a shine, you should be lasering. If your opponent is moving around unhindered, you aren't doing your job. Abuse the laser. This dosn't mean be blindly offensive though, don't take it the wrong way. Just because you're far from your opponent dosn't mean you have to approach. You just want control. You want to be overwhelming.
Ok, so now Marth. That Marth is quite flashy, which isn't a bad thing. I saw some nice combos, including tipped fair to spike. I can see that you understand the concept of spacing, and apply it quite well. The Zelda was obviously having trouble getting inside your sword (see the first stock in the second vs Zelda match). I tell all Marth's this: even though your spacing is good, it should be better. Marth's range and priority, combined with his ideally placed sweetspot and the fact that his sword is disjointed, is WHY he's such a good character. The better your spacing, the better a Marth you'll be. That should be your focus in matches. Of course, I'm sure you already knew this
That Marth is good, so there isn't really much else I can say. It's a little hard to tell based on a video wether you do this or not, so I'll say it anyway: Don't look for combos in a match. Focus on spacing, and combos will come naturally. Many new players just focus on getting that Ken Combo off, and don't realise that their opponent will destroy them because of it.
Like I said at the beginning of the post, you're both good players. Better then me. Keep it up, and you'll get even better!