It is interesting that they will likely feel they can ask you questions, and expect you to answer.
However, if you were to ask them questions regarding one of their beliefs they will not answer. For instance, "if the faithful and discreet slave is guided by Jehovah's Spirit, why do they continually change their beliefs?" or "I feel responsible for misleading people I studied with when I told them that the generation living in 1914 would see Armageddon in their lifetime, was that a Bible teaching or a mistake?"
They will not directly answer those questions in a satisfactory way. They will repeat FDS are men and not inspired etc. But likely, they will not say that they misled people and affected lives.
Their discussion will be a one way street.