They ARE nice people.
They nicely spend hours trudging through snow, freezing rain and unbearably hot temperatures disseminating information that the men give them to pass out.
They know what the men told them about God's name... oooh just wish they'd reiterate that whole point about the Roman Catholic Monk who made up the name "Jehovah" mentioned in their publication "Aid to Bible Understanding". None of the nice people seem to be knowledgeable about that.
And you are right! The nice people do "know the prophecies in the Bible and pretty much what they mean and what is on the horizon and beyond."... until their leaders change the prophecies in the Bible and pretty much what they mean for what is on the horizon and beyond. Right around then things get messy.
They are polite too. They believe it'd be rude to correct the group of men who analyze the Bible for them.
As for going door to door, they have been told to do it by scripture the leaders and won't stop up until this world's way of doing things ends the corporation sinks.
As for their hearts... well... go ahead and join; just don't ask any questions that challenge what the men say like others on the board have done.
They are really nice people.