I would agree with what Chris, Audi, Gu Ro Chen, and Polaris write.
Wu,
When one asks a teacher about where he learned his art, one does so with humility and respect. If genuine, no true teacher will have any problem with the question. I still think for one to ask to push hands or for him or her to "show" you his skill on day one is rude, whether the teacher is a real "master", a "pretender, or somewhere in between. Only my opinion. It is just that I have had rare encounters with these types who come into class. Some of these were just type A know it alls. Those I would refuse(As a senior student and a teacher myself. Those who waited, I would gladly show them or let them try anything pertaining to their level of developement.