I could follow the video pretty well. Anyway it seems like your techskill is almost all there but not completely so work on that obviously.
-Do easier setups for grab combos, I didn't see chain grabbing but if you can't do that a couple of upsmashes will work well too, (you seemed to get smarter by the end of the video and did this more).
-Cut out the unecessary flash, it looks like you picked up some bad habits from playing against a computer where youll do shffled aerials and dance around way to much when he respawns, or start a waveshine really far away from your opponent and try to waveshine up to him (you both did this).
-Wait for your opponent to make mistakes, you kind of just rush in there without waiting to see how your opponent reacts to things (like how he techs or rolls, stuff like that). Your attempts at mindgames are also easy to predict, you basically run around wavedash back like 2-3 times and run in with a nair or something, and that is your fakeout. Again I blame this on bad computer habits, but try and make a conscience effort to play smarter.
-You try to edgeguard with shinespikes way too much. Early on you got stage spike from your friends up B, if you are going to shinespike from the stage make sure you have ledge invincibility so you won't get hit like that, otherwise stick to bairs and d smashes on the stage, maybe you've been watching too much shined blind?
-If you can't think of things to do hang back and play defensive, spam short hopped lasers, fullhopped triple lasers, or short hopped double lasers (obviously not standing lasers). Make your opponent come to you don't go just running in and spamming attacks left and right hoping one will hit.
I hope this helped, it looked like you and that guy were about the same skill level which is good, but try and find someone who can absolutely destroy you because you will learn from your mistakes and become less predictable. Also play captain falcon he will make you a smarter player since he relies on techchasing and reading opponents so much.