NOTE: This turned out to be some kind of Marth vs Peach matchup guide ad not just comment on your vids. O.o
NOTE2: The people who hate me for me being an overconfident ignorant bstrd: Please don't flame me randomly without trying this stuff.. Most of it is from people who are said to be good against Peach.
I only watched your matches vs. XiF.
The turnip drop edgeguard that XIF did to you... I think you would time the up B for later, and hit the other side of the turnip and then tech off the wall. Just a tip if the edgeguard was annoying you.
Now. It's not flashiness that hurts your game. I only saw a few times where it seemed to get you punished, but I'd guess that was just mindgames's fault, not the flashyness's. One thing.. dthrow dtilt doesn't work all that well on a Peach who can DI properly, try to not use it so much. Fthrow is far better 99% of the time(Near the ledge when the peach is around 100% and doesn't realize that he should DI away and not towards the stage might be a good spot to dthrow, though).
Dont rush in so much with your nair/fair/whatever. Peach has to get close to you to hurt you.. What can the Peach do? I'd do a lot more utilts and play more defensively, sh back and catch turnip-> throw back to counter turnips. And only use fsmashes to finish comboes. Maybe some fancy wavedash-fsmash once or twice a match(For example, jump, see that they are shielding, landing wavedash backwards right next to their shield, they'll miss shieldgrab, tipper?).
Attack the peach when she's in the air floating, always. Don't let her get turnips, punish her when she picks them up. You can probably just charge in with a dash attack if the Peach is far away, because you can be sure she'll pick a turnip up. Don't count on it if it's a smart Peach, though.
Anyways, when a peach is floating above you, she'll have a really hard time getting to you. If you just sh and space a fair(don't move forward while fairing in general, doesn't work most of the time. Moving backwards spaced fairs seem to work well.)
Up tilt is also great, and if you know they'll come down with a FC fair or something, wavedash back and fsmash(Time it so it hits her before she hits the ground.).
Stay away from the Peach. I don't mean really far away where she gets the chance to turnip spam, I mean far enough so that her dsmash doesn't reach you. Space a lot of fairs(Not moving forward =/ They get punished x_x) and uair juggle when you get the chance. How I play against Peach is pretty much.. Wait for them to go aerial, punish them.
I saw XiF dash attacked a lot. You could shieldgrab them for a free combo.. But only when you think they'll dash attack, because grab or dsmash>your shield. Ah, how complicated smash is..
For the majority of the match, I'd just stay away, wait for her to get aerial as said, and punish. Your comboes seem pretty good, so nothing much to say about that. Try to finish with utilt sometimes, it's good and kills her early. Easy to hit with as well.
If the peach throws a turnip try short hopping backwards, catching it, and throwing it instantly back. This usually works surprisingly well, and the sh back gets you out of the fc's way. Space tippered aerials...and utilts.
If the Peach comes at you with a FC'd aerial and times it properly near the ground(if not, you can shieldgrab), you should just roll away. Don't bother competing with the Dsmash, you won't win..(Maybe with full shield a shieldgrab or fair from shield, or if you have the reflexes to light shield-shieldgrab/fair from shield. But rolling is safer. =/).
If the Peach is on groundwith low % and you are attacking, what do you do? Almost everything you do will get cc'dsmashed. So you have to do something that can't be countered by that. You can space a fair REALLY well. I'd say not very close to ground, and start moving backwards early in the fair. When you tip her with it and then move backwards, you'll be out of the dsmash's range. Win. The second one is to grab of course. And also all the full jump fairtippers and so on. But never do a middlehit aerial vs a Peach at 0-80% or so, it will get CCC-dsmashed.
DI-ing against Peach. You probably know that you should DI her fthrow up-towards stage for the max survival. But at low %'s you should not DI it, or DI it away, because Peach can follow with a dash attack if you DI it up-towards her. Dthrow you should always DI back, and then techroll back, and instantly roll or jump away. This will save you from all the follow-ups. You can jump from the uthrow, so DI isnt too important for that. I'd suggest to DI it back, though.
At low %'s, generally DI away from everything, escpecially uairs, because the uair comboes can really hurt. before 50%, or even after, depending on where you are on the stage, after you get hit by a dash attack, hold away and try to time a jump. Peach has some nasty weak hit-strong hit comboes and uair comboes.. :x
I'll repeat once again.. NEVER dash dance around Peach so that you at some point of the dash dance get into Peach's dsmash range. You're just asking for a dsmash, and the Peach will use it.
Edgeguarding Peach. Peach is quite difficult to edgeguard, especially if she floats above you. if she floats above you, I suggest a double jump bair, which I saw you doing, so that's good. However, if the bair will not hit, I suggest a uair, it's better than whiffing the bair. If the Peach is stupid and returns stupidly with double jump or float, feel free to spike, it's an instant kill. If the Peach is returning rather low, dtilt in my opinion is the best answer. Mindgame with dtilt/edgehog and you should be able to kill her(An example.. Peach is returning rather low but not sweetspotting, dtilt. peach up B's, dtilt again. And then they can't recover anymore, edgehog. What example was that? Ah well).
If the Peach recovers so that she can get on stage with just her double jump and float, expect an airdodge. most peaches airdodge every time when Marth is edgeguarding them, trying to avoid that fsmash. So if you know they'll do that, wait for the airdodge and punish with the move with the best knockback available. (I'd say dtilt tipper if near the ledge before they have hit the ground, fsmash works at other times. Up B is better than non-tippered fsmash, just harder to time and space.)
Blah blah, what else. Fthrow-fsmash tipper works at 0-10% if they don't DI, it's good to get them of the stage early on. Kills at Yoshi's Story with crappy DI. O_o'' Fthrow chainthrow works until like 20% maybe, tipper after a few fthrows. Then after taht in a while dash attack starts working, use that. And after that(100%ish) Wavedash-fsmash(If you just want the fsmash in without caring for tipper) or Pivot-fsmash(Really difficult, but master it and you can get a kill off every fthrow around 100% that isn't DI's away...). Fairs into Ken combo or fsmash... Yeah, I guess that's about it. Questions?
I'll write more when I think of more stuff. Please no OLOLOL NUB SHADDUP JOOR MAAF SOCKSSS-comments please, just trying to help.
