It was originally Jacobs home but Scrooge took it after his death. No one wanted to be with Scrooge and he lived a miserly life with no one to think of or care for him. He had driven people away from him that tried to care for him. However the house was turned in to offices which Scrooge rented out keeping only an apartment for himself.
How to live on his own
hi how are you
Yes, he showed Scrooge his own grave, untended, as no one would care or mourn his death if he did not change his ways.
The ghost takes Scrooge to re-live specific times of Scrooge's own past life and allows him to see the good and the bad of that life and to understand that these events are what made him and that he can not changes these now but he can make changes for the future
The spirit shows Scrooge his own headstone in the book.
In is own bed
He reminded Scrooge of his own questions "Are there no workhouses? Are there no prisons?" when asked for a donation for the poor and needy.
his own name.
He was in his own room
He told him to leave his counting house and keep Christmas In his own way as He (Scrooge) would keep it in his.
To highlight to scrooge his ignorance of what was happening in the world around him
Scrooge wants to know what the chain means, and why it contains the items it does. Marley explaines that his (Marley's) chain was forged to that size 7 years previously, and now Scrooge's will be 7 times longer.