Other mistake: When Chozen is buying vegetables from the villagers, one of the weights from the scale is knocked onto the ground. Daniel picks it up and realises that its not a real weight and breaks it in half. If Chozen wanted to cheat the villagers when he weighed their vegetables, he would need weights that were heavier than normal, not lighter plastic ones. Lighter weights would mean that Chozen would need to add far more of the light weights to make any amount of vegetables balance out, therefore he would be paying more for the vegetables than they are worth.
Other mistake: During the scene of the Bone Dance in the castle, Daniel shouts out "Behind you!" to the Japanese girl as Chozen grabs her. As he does so, the shot goes wide and you can see Daniel and Mr. Miyagi rise up and begin to run forward. The shot then returns to just Chozen and the girl, and when the shot goes wide again, Daniel and Mr. Miyagi are again just getting up and running forward.