Ok then let's look at some of your apologetics.
a) Secret knowledge of am impending disaster - This doesn't fit the JW's. They have been printing loads of literature about this and the Armaggedon has been part of the teaching of the JW's since very early. It's not a "secret knowledge".
Don't get hung up on the word "secret". The key interest of the Watchtower since Russell got together with Barbour has been the timing of the end. It pretends that its prognostications are based on unique knkowledge of the bible in a way that is hidden from other students of the bible.
This perfectly fits the criteria.
However these aren't conveyed in secrecy to the "leader" (the GB) because they find base their doctrine in the Bible, a very public book
The GB have stated frequently that the bible cannot be understood without their direction. This arrogance began with Russell who said that a person would be better reading Studies in the Scriptures than the bible.
Insulation from the outside world..not true (phisically).
JWs keep contact with non-JWs to an absolute minimum as you well know. This is a classic sign of a cult.
A charismatic leader that appeals to the desires of the followers - Completely untrue with the JW's. Their leadership since Russell and Rutherford became much less leader-centered.
On the contrary there has been a significant increase in emphasis on obedience to and praise of the GB. It appears to be far more so now than even when I left in '96. The fact that the leader is a group rather than an individual makes no difference.
without a given date-target, the JW's are much more relaxed about "the end".
Bullshit. "overlapping generation"?
There IS critical thinking inside the JW's. But it is often supressed
Suppression of thoughts and ideas is THE hallmark of a cult.