All of you have alo of room to improve, and I mean ALOT.
Whoever played the Sheik: I saw no wave dashing or use of needles, especially against Peach you should abuse the needles. Overall the Sheik needs alot of technical work.
Whoever played Peach: Your not that bad, but your not that good, your sorta like bolognese. That Young Link you played that spammed the DAir for God knows whatever reason shoulda have got more DSmash to the face. And I am also not sure why you FSmash so much...
Whoever Played Young Link: You spammed the Dair waaaaaaaaay to much, and you would have been punished for it if you were playing a better player (yes even if you L Cancel it perfect the lag is still that bad). Your only air attack should be Nair and maybe a bit of Bair, and only Dair when you have a good set up for it or your almost sure it will hit. You need more bombs too from what I saw, sometimes you shoot arrows instead of pulling bombs which is a no. Bombs have 10 times the versatility and set up for Nairs and Dairs that can get you stocks. The order of Y. Link's projectiles is Bomb>Boomerang>Arrows. And don't get into the fray so often use your projectile spamming to bait your opponent and rack up some damage to get the stocks.
Whoever Played Doc: Either learn how to play Doc or quit, no johns.
I only watched a few matches but this is what I saw, I hope it helps.