Terry: Good points all of them.
I recall during my angst when I was attempting to find out what religion is really true, well what Christian religion since I never considered any others, I asked the elder who I was studying with to come to my house to talk about it. Specifically, I wanted to know how he knew the WT religion was the one true religion. The conversation was pleasant and I recall telling him that I used to watch Jack Van Impe Presents regularly and was actually impressed with him for a while. Then I commented that Jack made a mistake that costed him his credibility in my eyes when he attempted to estimate the year of Christ's return being somewhere around 1998 which obviously did not occur. It was then when the elder mentioned 1975 and how witnesses believed the end of this system was going to occur then. My response, "That did not shake your faith for it certainly would've shaken mine?" He responded by saying that it was the overzealousness of the witnesses that caused them to believe that 1975 was significant and nothing that the WT actually did. Granted I later found the WT or Awake article (Oct 1969 I do believe) that certainly gave the impression that there could be something significant about this year though it never actually stated (in print) that the old system would've passed away that year.
The CHIEF CLAIM (those four premises you lead with) were something that I had seen similarly before amongst the Independent Fundamental Baptists churches that I had been attending back in those years I was watching Jack Van Impe Presents. They too, made similar claims that they had the only true teachings that lead to everlasting life and required similar commitments to the church's teachings and practices. They lost their credibility when the preacher's hard line stances began encroaching on things like children living at home past the age of 18 (I was 21 at the time still living at home), preaching urban legends as biblical truths (like P&G being run by satanists or the BEAST of Revelations being a supercomputer in Belgium), or him preaching that visiting other churches that you weren't a member of was the same as committing adultery against your home church. He backpedalled on that one in a most hilarious way when I reminded him of that comment later when he invited me to visit his church after I had left it and joined a southern baptist church.
I guess I can say that being exposed to the IFB's and later seeing through their bullshit helped immunized me somewhat to the witnesses teachings though it did take me some time and research to recover from almost being pulled in by them.