Hi David Yes some of the movements in the promotional video are not realistic, I have purchased the dvd though as I got it cheap, hoping there is something worth watching in it
In the video Ni Luh Putu blocks a staff strike with the handle of a keris, that must be one sturdy handle! Most keris if you hit them with force either to the handle or sheath would result in considerable damage.
The Keris is mainly an esoteric weapon but it can and has been used in a physical way also. Its not the best weapon for physical protection but maybe as a alternative.