I love to help and improve this TAS run but the re-recording Emulator keeps on giving me the error message.
http://www.youtube.com/watch?v=bk0u94bf21M
About the flagpole trick: Look at 1:24 of the video, see how much faster it is to start the celebration sequence.
Now that I've watched the rest of the video, I can say that:
Bowser Junior in 8-Tower1 can be possibly improved by:
*Ground pounding Junior after the first hit. If this proves to be impossible then the other method is to:
*Hit Bowser with the normal jump like the TAS shows then, go away from Bowser and wall jump back to perform a Shell Spin, this should knock down Bowser JNR as soon as he recovers from the first hit, then you can finish off with a Ground pound possibly saving a few frames.
When you enter doors it's faster (in Real TAS time) to enter close to the centre as possible I think mainly because:
If you start to open the door as soon as possible, Mario/Luigi walks to the centre and then goes through the door.
However if you run to the centre of the door and open it, Mario/Luigi would go straight through the door, without needing to walk to the centre first, possibly saving a few more frames.