Re: The Joker's background?
On daily basis ? hmm doesn't sound right. if that was the case then he would change goals too. his main focus was still to crumble the city, destroy Dent and make Batman break his rules. When the Joker reinvents himself in the comics he also changes motivations.
Giving Joker a backstory is the worst thing you can do to the character. him having decent education or just a thing for chemistry and art is fine but too much backstory takes all the mystery out of the persona of the Joker.