First of all I wouldn't allow him to ramble on so long without 'overcoming his objections'. He covered so many subjects it's hard to know where to begin.
But just for starters, I would have stopped him a few times and asked such questions as these:
would you want your family to die with a FALSE hope based on following blind guides? ....guides who cannot seem to make up their mind about anything except that THEY are the only ones to be followed... on threat of d/f and losing your beloved family?
Do you really want your faith to not be founded on anything except the "good feeling" it brings you?
It's not without reason that Jesus warned against this. For example, he talked about those who accumulated teachers to tickle their ears. And when asked about the last days of this "wicked" system as you call it, his very FIRST sign was that others would try to mislead you and would put THEMSELVES as the spokesperson for Jesus. Does WT do this? And would YOU want your family to be caught in that position when he returned?
And then I would say: Let me ask YOU a question ....Would YOU personally cut off one of your beloved family if they decided NOT to follow WT teachings? The RC stated that one of the cruelest things a person could do to another human being is to SHUN them. This can cause untold psychological trauma and suicide. RC called WT a "captive organization" because of such policies. Do you think this policy could possibly "disrupt the peace" your family has?