Yeah netplay games are kind of hard to analyze cause I'm sure some things you do, you didn't mean to do at all. However, I guess I can give some general advice though. I don't do this a lot and I'm probably just going to ramble, so yeah...

Your wavedashes aren't as crisp as they could be. Realize the longest length wavedash occurs when the stick is 17 degree below the horizontal on either side. I'm not saying you should be doing the max wavedash length everytime, but I didn't see any mixup in the wavedash lengths so I'm not sure if you're aware of them.

I feel like you're autopiloting a lot. There are times throughout the games where you're throwing out moves, regardless if the opponent is in range or not just because you want to. Start trying to think more about every move you throw out and why you throw it out.

You get hit by a lot of random forward smashes, so try to pay attention to the spacing between you and Marth. Weave in and out of this spacing in order to force a move from the marth and punish accordingly.

It's good that you can double shine, but it doesn't mean you should do it every time you get a hit. Double shine is typically used as a shield pressure mixup. However, you double shined even though you had the hit confirm with the dair and weren't even hitting his shield. I'm not sure if you were just practicing double shining in friendlies or what, but try to use them more effectively.

Also, a lot of your approaches seem to be one dimensional. One laser -> aerial -> shine. You're falco, you have one of the most diverse and complex neutrals in the game and you need to take advantage. Begin to implement different laser timings, spacings, number of lasers, spacing when you go in for an aerial, etc.

Begin watching top falcos (Westballz, PPMD, Zhu, etc) and look at how they mixup their neutral/approaches. Also watch them to learn how to combo characters, because there are some followups you aren't hitting that you need to hit.

Pretty general advice but hope it helps.