Well, killing Thanos in the comics can vary. Sometimes it's a surprise twist or a heroic sacrifice that leads to his downfall. Different story arcs have different methods of taking him out.
Sure did. Thanos is known for causing a lot of destruction and taking lives in the comic universe. His actions often have major consequences for the heroes and the overall story.
Yes. Thanos' clashes with the Avengers in the comics led to the demise of some members. His might and strategic thinking gave him the upper hand in these battles.