Batman & Robin
None. He is just extremely smart and good at building devices that help him fight crime.
Batman became a crime fighter due to the death of his parents at the hands of a robber. So Batman fights crime ... that's what he does.
Batman's parents died in Crime Alley when a criminal shot them.
"Batman Beyond"
When Batman was not fighting crime, he was billionaire Bruce Wayne, owner of Wayne Enterprises.
Because most "crime fighters" are vigilante.
at crime fighting yes
Crime Alley
Batman wants to make his city safe from crime so that no child will have to experience the same tragedy he did.
Yes they both like each other, but decided not to date each other because they did not want it to interfer with crime fighting in the Justice League.
Batman fights crime in Detective comics, in the TV version with his much younger cohort Robin, who is an acrobat.