Well, it could be due to a build-up of frustration and a sense of hopelessness in trying to reform the Joker. Also, maybe in that particular comic's storyline, the circumstances are extreme and Batman makes a desperate choice.
Most of the time, Batman refrains from killing in the comics. His mission is to rehabilitate villains rather than eliminate them. This approach makes him a symbol of hope and a hero who upholds the law without crossing the line into lethal force.
Yes, in some comic storylines, Batman has been involved in situations where Superman's fate is uncertain or where actions could be interpreted as leading to Superman's demise.
In the comics, Batman typically doesn't kill. His mission is to rehabilitate and reform, not to end lives. This moral stance is a core part of his character and the way he operates in Gotham.
In the comics, Batman doesn't die at the hands of Bane. Bane is a powerful adversary, but Batman finds a way to overcome his challenges and live on to fight another day. Their confrontations are epic, but Batman's resilience prevails.
Batman typically refrains from killing the Joker in the comics. This is because Batman believes in justice, not vengeance, and killing would go against his principles. Also, keeping the Joker alive creates ongoing story arcs and challenges for Batman to overcome through non-lethal means.
In most comic storylines, Batman doesn't kill Superman. Their relationship is complex, with battles and rivalries, but outright killing is rare. It goes against Batman's moral code and the general tone of their dynamic.