Cornstalk
Smash Journeyman
Got a few for Lizardon worth mentioning:
Jab 1 hit stun
The hit stun on Jab 1 is almost non-existent. This means you're practically required to mash the button as fast as possible to make sure Jab 2 lands at low %, other wise the opponent will get their feet on the ground and can simply shield Jab 2 and Jab 3. The solution here is to add a few frames more to Jab 1 hit stun (couldn't get you exact numbers, but 3-5 frames would likely be enough) so a slight delay in bring out Jab 2 doesn't cause the entire jab string to be escapable. The rational behind this is more along the lines of consistency with other jab strings, as I haven't noticed escapable frames on any other jab.
Back-Air landing lag
This is a risk vs reward issue. The landing lag on this move is pretty close to what Link suffers on his D-air. It requires a sweet spot to be an actual threat of KO. There hit box is also fairly small and quick, leaving Charizard vulnerable for most of the move. A small reduction in landing lag would make this attack a little more worthwhile to take a shot at using, particularly against skilled air-dodgers who currently get a free punish against a charizard that tries to use this and lands on stage with lag.
To the point: The landing lag is not in line with the KO power compared to characters with similar powerful but much safer attacks
Up-Smash (lack of) Linking Hits
The hit boxes on this move are atrociously spaced out and strange. Considering moves like Link's F-smash and Zero Suit's Up and Over-B were patched to be better about linking, there's no reason for Charizard to be left out in the cold. The move currently and frequently fails to connect the multiple hits. This can often lead to weak knock back that leaves Charizard vulnerable to counter attack despite successfully landing a smash.
Up-B Custom 2 (Rising Cyclone) often has the same problem. Sure it's a custom move, but why shouldn't get it get the same link-friendly fix that other moves have received?
So there you go. 3 moves that could use the tiniest of tweaks to be consistent with the rest of the cast and 1 move that has too high of a risk for the reward problem.
Jab 1 hit stun
The hit stun on Jab 1 is almost non-existent. This means you're practically required to mash the button as fast as possible to make sure Jab 2 lands at low %, other wise the opponent will get their feet on the ground and can simply shield Jab 2 and Jab 3. The solution here is to add a few frames more to Jab 1 hit stun (couldn't get you exact numbers, but 3-5 frames would likely be enough) so a slight delay in bring out Jab 2 doesn't cause the entire jab string to be escapable. The rational behind this is more along the lines of consistency with other jab strings, as I haven't noticed escapable frames on any other jab.
Back-Air landing lag
This is a risk vs reward issue. The landing lag on this move is pretty close to what Link suffers on his D-air. It requires a sweet spot to be an actual threat of KO. There hit box is also fairly small and quick, leaving Charizard vulnerable for most of the move. A small reduction in landing lag would make this attack a little more worthwhile to take a shot at using, particularly against skilled air-dodgers who currently get a free punish against a charizard that tries to use this and lands on stage with lag.
To the point: The landing lag is not in line with the KO power compared to characters with similar powerful but much safer attacks
Up-Smash (lack of) Linking Hits
The hit boxes on this move are atrociously spaced out and strange. Considering moves like Link's F-smash and Zero Suit's Up and Over-B were patched to be better about linking, there's no reason for Charizard to be left out in the cold. The move currently and frequently fails to connect the multiple hits. This can often lead to weak knock back that leaves Charizard vulnerable to counter attack despite successfully landing a smash.
Up-B Custom 2 (Rising Cyclone) often has the same problem. Sure it's a custom move, but why shouldn't get it get the same link-friendly fix that other moves have received?
So there you go. 3 moves that could use the tiniest of tweaks to be consistent with the rest of the cast and 1 move that has too high of a risk for the reward problem.