Heaven: That the gates of heaven closed in 1935.
I believe that has changed and the gates are once again open. Maybe someone can verify that.
Minimus: other churches (including mine) do believe in a thousand year reign, but all will live on earth. (Associated Gospel, Pentecostal, Charles Stanley, David Jeremiah to name a few)
Some things JW's believe that are not actually Biblically provable:
That Jesus is Mediator only for the 144,000
That the 144,000 have heavenly hope vs Great Crowd with earthly hope
That Abraham, Isaac, Jacob, David have an earthly hope while the janitor down the street, because he is a JW and a feeling, will have a heavenly hope
They reject the divinity of Jesus despite the biblical evidence and yet accept that he is Michael with flimsy evidence of three scriptures.
That Jesus, Michael, is also Abaddon, the Destroyer and that the locusts are Jehovah's Witnesses.
Acts 9:11They had as king over them the angel of the Abyss, whose name in Hebrew is Abaddon, and in Greek, Apollyon. [a]
That the New Testament is written for and about Jehovah's Witnesses
That God has rejected the Jews and the Jehovah's Witnesses are now the Spiritual Israel.
That the JW's are the true witnesses of God, yet in the New Testament we are the witnesses of Christ.
Acts 1: 8 But you will receive power when the Holy Spirit comes on you; and you will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth."