What about games that use uninitialized RAM for random numbers (or other quirks of behaviour)? Is there a tool for nesbot that cleans RAM before starting so it'll be like in the TAS?
The biggest thing that makes a TAS interesting is going way faster than the devlopers expected you to - think the Sonic Advance 2 TAS, and TASes that glitch through walls and sequence break.
After that would be needing to strategize your movement based on what's around you - things like acceleration and deceleration and being able to bounce off walls/enemies, for instance. It also leads to a more aesthetically pleasant 'curving' around corners instead of just ramming up against them until you spill over the edge.
The way this computer works is a little different to the way you'd expect - for instance, google chrome crashes if you edit through a save as dialog after closing it only on this computer.
Could you try it again with Hourglass r57 (and without carrying over your .cfg file to the new version or changing any options from their defaults)? When you play the movie in that version, a dialog will appear telling you that the movie was recorded in an older version and asking a question. Try answering both Yes and No on separate playbacks and see if either works. Also check to see whether setting "Runtime > App Locale > Force Japanese Locale" has any effect.
Yes: 6141 timer vs 6037
No: No desync happened
That was easy :)
If you have Windows on your computer (or some other computer you can use), it should be easy to watch the movie directly, and the quality will be much better than on Nicovideo or Youtube.