Welcome, Northern Star
I am not and have never been a JW. For reasons that included a loved one, I began a "study" with an elder about a year ago. Like you, I made it clear that my goal was to be educated with respect to JWism - not to convert. After some time, the elder realized I knew more than a person whose door was knocked on and opened up in some areas of information. Like yours, my conversations would last 4-5 hours a week. There were a variety of emotions that were experienced - more for him than myself.
I love what you're doing. I wish more non-JWs knew about this insidious cult. If you want this to continue, I have one recommendation: SOLIDIFY A RELATIONSHIP or they'll bolt - especially if they can control whether the meeting happens or not as you have to expect them at YOUR house. Make snacks so that they know you put work into their presence. Right now, killing 4-5 hours at one location is a gold mine for them. They won't want to lose you but they will discard you like a ladies monthly item if too many of your questions start to come off as anti-Watchtower.
J.W.'s are generally Org-deluded or self-deluded - or both. - The Searcher
Sadly, this about sums it up - the difference is one has no self-confidence and the other has too much.
I will be watching your posts carefully to see if you reach the same conclusions I've reached. :)
Good luck and good to have you here!