Jonathan Roberts wrote:
My guesses:
1 - If there's an imbalance along the stick, the shorter end is lighter and provides less friction.
2 - When holding in portrait mode, any imbalances due to wind resistance are exaggerated as the weight is spread out away from the axis of rotation. Spinning in landscape mode doesn't have this effect so much as the weight is closer to the axis. When spinning along the thin edge, the rotation is more stable because any imbalances will tend to correct themselves back to the rotation where there is least wind resistance.
3 - Not really sure, but maybe something to do with what @electronmom2000 said. It doesn't work for me with a glass though, so maybe it is something to do with the static electricity.
4 - Cereal has added iron, which might be enough to be attracted by a magnet if you take out most of the friction.
5 - You have created an updraft of warm air from burning the tube for a few seconds and the last bit is light enough to travel up it.