EDIT: My apologies to General. I based most of my initial stuff on the Ganon because Ganon is generally trickier for Marth to fight, but that peach is actually decent, and does punish some of the things I pointed out before. He has bad recovery and virtually no edgeguard tho, so again, your edgeguard and recovery are not really being tested (yet you're still failing sometimes to kill/get back so work on these things).
Couple of other things:
When you go for a move and miss, you instinctively shield. I'm guessing this is because you are not used to missing, and are not certain whether or not you are about to be punished or not, so you just shield and go from there. Try to know when you can or can't get punished (and in general, when approaching, do not bank on connecting a move and avoid approaches that are guaranteed to be punished if they fail).
As a result of this, sometimes you get stuck in shield and don't get punished - which is where you need to roll backwards or WD out of shield. I did not see any WDing out of shield in these matches. This is an incredibly important technique not just for responding to hits on your shield but just fluidly being able to continue your movement in and out of shield. If you do not WD out of shield well practice that until it is smooth as butter.
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Tho it has been acknowledged I'll just reiterate that it is difficult to critique this because if ur not getting beaten or at least challenged your flaws don't show or stand out. But this is what I'm seeing:
Fundamentally he looks very solid. He's quick when he needs to be, generally understands how to space with marth (tho matches against Ganon and Peach are about the easiest for marth to space against - if you have any fox/falco/cfalcon/marth/doc mario matches those would be better).
It looks like a lot of these tech chases he is getting are based on really predictable techs that he is also guessing on - not reacting to because he knows his opponents are predictable. This is pretty much an impossible thing for him to improve upon unless he fights trickier opponents.
The edgeguard does look noticeably soft. His opponents recoveries are pretty much completely straight forward (ganon pulling back on high up B is pretty much the lowest level of tricky recovery and even that was working sometimes). Against good opponents Marth absolutely needs to nail those edgeguards or he will get punished and just lose. Marth being a top character is dependent on him executing edgeguards at a high success rate.
There are a couple of sloppy approaches he uses that would get punished heavily by better players. You pretty much want to get your marth to the point where it is NEVER fsmashing a shield, and he fsmashes shields a lot (and also connects fsmashes a lot where they SHOULD have been shielded). He just needs to be more patient and disciplined in spacing fair/nair/dtilt/DD grab. Which brings me to the second issue - too aggressive with fair. Sometimes he goes for rising FH/SH fairs coming at the opponent, which should be shielded and punished. Late fair at maximum distance or fair with some space and immediate dash away to bait them in.
Also, when he does end up out of position either because he full hopped above or got hit above he tries to come down on the opponent with dair - Don't go for this. It's really predictable and easily punished. Just get back on the ground. Usually if I get knocked up in the air, especially against slow immobile characters like peach/ganon, I just try to save my jump and fade to the edge. It sounds risky but with the 2nd jump you can solidly evade these guys if they do actually come after you and marth is most vulnerable directly below himself. If you do find yourself, say, in the very middle of FD, use side Bs and air dodge but DON'T DAIR. Just get down on the ground. One more thing on dair - connect it properly. You're hitting with middle of the sword and you're also missing the L Cancel. Work on this bc dair in general is really really useful (just not when out of position).
Lastly, defensively some of this DI (most is good) looks a little suspect and most of the moves he's getting hit by are very standard grab combo or tech chase hits that should be seen coming even if unavoidable and DI'd perfectly EVERY time. When recovering, do not 2nd jump early - save to sweet spot edge unless they commit to come at you, in which case use it to space fair properly if necessary. His techs looks really predictable himself - work on reading what they are going for and teching appropriately.
This last part is probably where he needs the most improvement. Players who are accustomed to dominating do not typically DI, tech, or recover well when put under pressure by good/better opponents. DI/teching/recovery is probably the most difficult and advanced part of the game just generally speaking because it requires somebody ****** you to learn how to improve it.
Again, most of this is just an educated guess just watching his matches against characters that really do not force Marth into very difficult spots that are also being played by significantly worse players than he is. Even players of this level playing the characters I mentioned before would do a better job of exposing his weaknesses, so if you could get any matches like that it would be easier (tho I still think all the above advice would apply).
