The "portly gentleman" was seeking a charitable donation to help feed the poor at Christmas.
The large man wants Scrooge to mend his ways and change his selfish behavior so that he can avoid the same fate as Marley - being bound in chains and condemned to wander the afterlife as a tormented spirit. He warns Scrooge that he still has a chance to change, but time is running out.
They were not poor. They were businessmen of the time seeking charitable donations that they could use to help the poor and needy at the time
A donation to a charity for the poor.
Jacobs return was the start of the changes that Scrooge was to undertake before Christmas Day. Marley tells Scrooge that he (Marley) will walk the earth for eternity because of his attitude to his fellow man. It was a punishment that he did not want Scrooge to endure
They were playing charades
no-one went to Scrooge's funeral as he was a selfish and inconsiderate man that no-on liked
Fezziwig was Scrooge's master, not his teacher. Fezziwig was Scrooge's employer when Scrooge was a young man learning the trade of business.
These points were to make Scrooge the man he was to become
He was a good business man and a good friend to Scrooge
Himself
Ebeneezer Scrooge
When young, Scrooge worked for Mr. Fezziwig, a genial and generous man.
He teaches Scrooge that you can change your future if you become a better man.
The dead man was Ebenezer Scrooge's former partner, Jacob Marley. Scrooge discovered who it was when Marley's ghost appeared to him in chains to deliver a warning about his impending fate if he did not change his ways.
He was Ebenezer Scrooge the main character who turned from a miserly old man in to a caring person