Ref code: umedgeguard?
You're having lots of troubles with lasers. It seems more like a mental issue than anything. You're rushing in too fast, taking the hits from the lasers and putting yourself at a disadvantage. Take it slow and approach patiently. Even if you do get sniped from a distance, the damage from a laser is almost negligible if you consider the chainthrows and gimps that you have against Falco.
Your DI looks a little off, so you're taking a lot more hits from each combo than I feel you really should be.
You do this thing where you jump then immediately double jump. That's bad, because it leaves you with very few options, especially with Falco close. I'm not really sure what you're trying to accomplish here, but if you do have a good reason for it, don't forget about your Dancing Blade. The first one can float you a little and it might throw Falco off.
But yeah, once you get around the lasers, you'll find yourself in a much better position against Falco.
Oh yeah, and stop eating the light shield edge hog. Easier said than done, I know, but you should consider air dodging to the edge to recover or Dolphin Slashing early so you don't hit his shield. If you go straight for the ledge, you're dead, so mix it up.
Ref code: otg1
You seem to be uthrowing a lot in situations where uthrow isn't the best idea. Once you get your opponent over eighty percent, your options out of the uthrow start declining and, especially at the ledge, a dthrow is often better. You're looking for kills above all else and the best place to get them is when your opponent is off the stage.
Why do you ftilt after dtilt?
You use the Dancing Blade too fast on the recovery. It gives you distance partially based on your momentum. Meaning if you're drifting forward already, you'll get more distance as opposed to if you're just falling straight. So don't use it immediately after getting knocked off.
When you recover close to the stage (like when you haven't been knocked off very far) you seem to Dancing Blade first then double jump. This eats up two of your options when you don't really need to use both. Save your Dancing Blade, at least.
Also, a minor point. When you're double jumping to the ledge, be careful not to go too high. You don't want to get caught by a random dash attack or fsmash or something.
Ref code: QDLRZ
Your Marth feels very slow. I dunno. It seems like a lot of times when you should be doing something, you can't because you're caught in lag. It's not the usual problem of fsmashing too much, either, which is surprising.
Most of your lag is coming from rolls, missed jump cancels and dairs.
For starters, learn to wavedash out of shield if you can't already. You're getting stuck in shield a lot and your only way out seems to be to roll, which hurts because it disintegrates any pressure you had on your opponent. Of course, learn all the out of shield options, too. For the moment, the only one you seem to be using is the dair.
Which is bad. The dair is unwieldy and slow. You're wasting a lot of time on it.
Once you do that, you'll find yourself having more time to dash dance and you'll be able to control the stage better.