Satan being allowed in the new Paradise on Earth I recall reading a scripture from the Bible with two JW's that said in the new Paradise Satan would be allowed. I questioned that with them and they smiled and said "yes".
Can you tell me in what book and verse of the Bible it says this?
Jehovah’s Witnesses teach that after Armageddon Satan and his demons are thrown into the abyss (a state of inactivity)and a 1000 year long judgment day will begin. 
During this time earth will be made a paradise, mankind will attain to perfection, the dead will be resurrected  all mankind will be judged.
A brief description of judgement day can be found here

At the end of the 1000 years a final testing described as taking a little while will take place when Satan is released and allowed to try to mislead mankind on final time.

The scripture that you are looking for is 
Revelation 20:3 it reads from the new world translation :


  And he hurled him into the abyss and shut it and sealed it over him, so that he would not mislead the nations anymore until the 1,000 years were ended. After this he must be released for a little while.


And vs 7&amp;8 read:


  Now as soon as the 1,000 years have ended, Satan will be released from his prison, 8  and he will go out to mislead those nations in the four corners of the earth, Gog and Maʹgog, to gather them together for the war. The number of these is as the sand of the sea. 


Good news is this time of testing is brief and Satan is then eternally destroyed.