Well, in the comics, Thanos has had multiple instances where he seemed to meet his end. However, the comic world is full of surprises and plot devices that can bring characters back or change the outcome.
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.
Thanos has died in the comics at certain points. The circumstances and the permanence of his death can change based on the creative direction of the writers and the demands of the ongoing narrative.
Well, Thanos met his end in the comic when his plans were ultimately thwarted by the combined efforts of multiple superheroes. His own overconfidence and underestimation of his opponents played a role in his downfall.