How can Satan operate on earth and re-enter heaven if he was cast into hell?

If Hell was created for the fallen angels and their leader (Matthew 25:41) , presumably before the Fall of man, how is it that Satan is subsequently able to tempt Eve (depending upon your interpretation) and Christ, wander the Earth (1 Peter 5:8) as its "prince" (John 12:31), and even gain access yo heaven from which he was banished to hold audience with God, whom he betrayed? And if Hell was created for the fallen angels then what does Revelation 12:9 mean when it refers to him being cast down to earth? Is it possible that Satan continues to influence earth from afar even while enduring his torment, and that God still employed his 'services' as an adversary?