I got some things here that will improve you very much if you can get them fixed:
-There were a lot of times where you would use Nair after getting hit or when landing, but you failed to hit the autocancel window so you suffered a lot of lag. I am guilty of this too so don't worry, but try to get rid of this habit, Nair is only useful if you can autocancel it. If you are in a position where you have to land, try to aim for the autocancel. If you are too low to autocancel you can always use a midair jump to reposition yourself. If you are out of jumps the next best thing is to land with Flamethrower to reset the situation or if you expect them to catch your landing trade with a Rock Smash. This is by far the biggest thing to improve yourself, it will blow your mind.
-You rolled too much. While rolls are much safer in Smash4 than other games, Charizard doesn't have a very good roll so you should limit it into situations where you want to get out safely. Charizard cannot play a crossup game with rolls. Only use rolls to get away. Whenever you roll try to think why you did it.
-Too much Flareblitz. The move is super situational. It can be used against Yoshi at midrange if you read an egg toss, but it's quite risky for little reward. Just keep powershielding the eggs, eventually you will get too close for him to throw eggs.
-Against Yoshi DownB, Uptilt easily beats it, your wings are invincible during the move. It has the best safety/reward ratio. Usmash and UpB are more risky, but go for them when you think you can get a kill.
-You landed so much with Bair. This is almost never a good idea, bair has a ridiculous 40+ frames of lag. That is unacceptable. Replace those Bairs with those Flamethrowers and Rock Smashes. Oh and sometimes it's ok to land without doing anything. Your opponent is waiting for you to act so he can react to it. If you do nothing there is nothing to react to. It's very hard to react to something not happening.
-Use more grab. Charizard has a very good grabgame. His pummel adds a lot of damage before throwing them. Use Fthrow or Bthrow, whichever send the opponent offstage. Then proceed to edgeguard with something. If they go for the ledge feel free to use Flamthrower to rack up damage (no as useful against Yoshi because of jump armor). If they recover high that is the moment to use Bair. This thing can kill at 60% easily offstage if you hit with the tail. If you read them airdodging the bair, just wait it out and upB them as their airdodge ends for a very early kill.
-You didn't use that much Jab or tilts. Charizards jab should be one of your most used moves. It's very fast for it's range, it catches people who try to spotdodge your grabs and it does good damage while launching them in a position that is very advantageous to you. There is also the setup for UpB doing Jab1 -> Jab2 -> Fly. This is easier when you catch the opponent midair. At 100% jab can become a killmove because of this.
Ftilt has a lot of range and is a decent poke. If your opponent is charging towards you you can simply run away and Ftilt out of the dash.
That's all I have to say, if you can implement all of this into your game your Charizard will easily be at least 3 times as good as it is on the video. There aren't even that complex things, just focus on them one at a time.
Post another video later and I'll see how much you have improved.