every body always mentions the kipping......have you ever tried to do one rusty??...think there a skil to learn correctly in there own right....most good crosfit gyms would get you doing strict pull ups first....and if you cant do them , do them banded...
one thing that they should be real carful about in my opinion is the Olympic lifts....and dead lifts....oly lifts are very technical ....and to some degree the dead lift theres that bit of film of the guy that runs crossfit...forgot his name...but hes with Jason killipa doing deads....and they guys form is frighting