for the first arm trick: the camera does not show when he actually does it. when he describes to the audience how to place their hands, it is impossible to acutally do it. when he points to the audienc he releases his hand and re positions. to reposition it you take your right hand and turn it as far as you can to the right until your thumb points down. then reach over and interlock your fingers with your left hand. you can then twist your hands to the left.
for the one with the girl (sensation trick): he taps her back when he is telling her what to do and she refers to this as the taps she felt. when she says she felt the sensation that is because as you can see he rubs his hands together to create friction and the feeling she had was the hairs on her arms prickling as his hand (with heat friction) went over her arm.
for the one with the table and the arm raising. the pressure the guy felt was the pressure of the magicians left foot touching his foot. he pressed down on the guys foot when he wanted him to lift his arm. this is the pressure.