I'm not experienced with TASing, but I've spent some time with normal speed runs of this game. In 8-Tower2 I have found that you can leave the green floaty block snake behind shortly after the level begins and run across the spikes and jump around to reach the check point directly before falling to commit suicide. I would make a video, but I lost my game cart like two years ago. I have timed this to be faster than just sticking with the blocks the whole time, but it may be different in a TAS because of how slow the overworld is. Also, you'll have to use regular ol' Mario to finish up the game. However, I have finished the final castle with 706 on the clock without using the R button in the room of flames with regular ol' Mario. I'm not sure how that compares to how the TAS does it because terrotim does not enter doors at the earliest instance possible (which stops the game clock earlier, but I'm guessing is slower in real time).
I'll just list a few techniques in the last castle I used that differ from the TAS, but I don't really know if they're faster or not:
- In the second room I would jump directly onto the first block and then ground pound the '?' button block. I found this to be faster than jumping off the right wall, but I didn't wall jump off of the middle block after the room has spun.
- In the big thwomp room I would jump to the right side of the big thwomp's smashing pedestal directly after ground pounding the '?' block. From the side of the pedestal I would wall jump and hold left, landing on the left side of the '?' button.
- This:
http://www.youtube.com/watch?v=e9gqxwvMy0I !