Scrooge heard the sound of his nephew, Fred's hearty laugh.
This refers to Marley's foretelling of three ghost who would visit him over three nights each would afford Scrooge the time to help him consider his own existences and allow him to change his ways else be prepare to suffer eternal damnation
Initially by sending him a prize turkey then by offering him a pay rise and insists that he use more coal on the fire to keep warm
Firstly a loving yet very poor family, the loyalty of his clerk Bob who toasted Scrooges health, then reaction of the whole family especially Mrs Cratchit to hearing Scrooges name
Marley tells Scrooge to expect three more spirits to visit him that night.
Three ghosts
Merely explains that without their council Scrooge may expect the same fate as he was suffering - everlasting torment.
This refers to the Ghost of Christmas Yet to Come . Scrooge is unaware of whom the people in the scenes refer to but is starting to guess it might me him and wants the ghost to tell him so
Scrooge tells Bob to have the day off if he really must but be in all the earlier the very next day
Scrooge had no more family following Fans death
I am Christmas past.
Marley appeared to Scrooge and warned him about changing his behavior. Marley also told Scrooge he would be visited by three ghosts.
When Marley's ghost visited Scrooge he warned him about the ghosts and his behaviour.
This was Marley telling Scrooge that he (Marley) was allowed to come back to Scrooge to tell Scrooge of his inpending eternal life of torment should he not make changes to the way he lives his life now and sees mankind as his business not just the money he can get from them
He states its "Christmas day"
Marley appeared in the fist instance and warned Scrooge that his miserly life style and attitude to others would see him suffer eternal torment in the next life and that he (Marley) had been allowed back to this life just once to warning and help him