Hello and welcome to the site Mario3264!
This site is for superplays, hence the name of the practice,
Tool
Assisted
Superplay. We aim to make and publish runs that exceed human abilities, typically represented by the goal of going as fast as possible, and this is seen by
our approach the games we TAS.
In particular, one unique property of TASing is since you have (theoritically) infinite time, you can fix any mistakes in your play. In fact, you can see every facet of the game at any given frame - you can access the entire memory of the console your game runs on at any given frame, and kind of see everything.
Kind of like God playing a game; he can predict everything, has perfect knowledge about the game and even the console quirks (that he can use to go faster, of course) but he has the same controller as everyone else, and does the same things that an human could do.
So mistakes in superplays, especially important ones that waste a lot of time (like there are quite a few in this movie), does not mean the TAS is up to quality standards, especially for games on the Super Mario World engine,
which has been studied to death (game resources page).
It seems you are not aware of all the tools at your disposal (see
http://tasvideos.org/TasingGuide/AdvancedTools.html which has a nice primer on this.) In particular, check out TAStudio which is a built-in easy edit interface for TASing that allows you to see every frame in a piano roll. TASing with savestates is mostly obsolete with the advent of tools like these, and you don't have the problem of not being able to go back to earlier in your superplay (because with the piano roll, you can jump to every single frame of your superplay.)
Finally, if you want to share unfinished TASes,
use the userfiles and make a post in the
appropriate forum thread.