The only thing that can come out of this? My family may begin to shun me, but as I said, they're not baptised or anything, they're only studying the Bible, so this conclusion doesn't necessarily follow from the premises. It's just a mere possibility.
I think that you are a very bright person. Seems like you know exactly what to expect, based on their typical behaviors and practices. That's great.
Based on that, he came to the conclusion that further discussions won't be necessary.
That takes care of their job. From day one they have not mentioned a single shred of interest in you as a person. Seems like the conversation was all about your thought, but none about if you were ok during the time they didn't know about you.
I have the feeling that they just "checked the box" with you. That should be fine (in my opinion) for all practical purposes. The issue here may be your relationship with your family.
I know that you are handling all the logical, philosophical and knowledge-based discussions beautifully. HOWEVER, if I may suggest something, with family, that kind of conversations alone (not saying that they should not happen) may not help them maintain a relationship with you. If you want them not to shun you, there may be more to do than just reasoning about your reasons not to be a JW.
Capitalize on the fact that the elders and nobody in the congregation bother inquiring about how you are doing all this time until they requested it. Mention that the elders left you and have no interest in seeing you again because "I have it all figured out." In other words, sine the investment here is not doctrine only, but also your relationship with loved ones, please talk about feelings and feeling-related things.
You may get some sense in the fact that you can show them that the congregation has no interest in you as a person, nor in "saving" you, leave alone what you have to say about your and their believes.
Please keep those things in mind. They may come handy to help family make the right decision regarding your relationship with them.