lv4fer -
I am in the same basic spot you are, except that I have been out for a long time, but have recently begun again trying to explain to my dad (an elder) why the WTBS cannot be the "truth".
Many of his responses are very similar to the ones you mentioned.
I worry daily that I will end up alienating him, and have many times called him to make sure "we were ok". He has told me that he will not "shun" me reguardless of my beliefs, but I know that at some point he may feel he has to.
Keep it simple, ask him "why" god needs an organization on earth? If he is at all like my dad, it will be all about "the work".
I intend to use the Luke 21:8 reasoning to show him (my dad) that the WTBS cannot be the one... not sure when I will, we are supposed to go fishing next Friday... but I want to take a break from these conversations.
hang in there.