Lana Lang did not marry Lex in the comics. The comic plots didn't lead to such a union. Their characters had separate developments and romantic involvements.
It varies. In certain comic arcs, Lana Lang may face life-threatening situations but doesn't necessarily die. The fate of her character can change based on the creative direction of the writers and the demands of the story.
Lana Lang is a character in DC Comics often associated with Clark Kent (Superman) from Smallville. She's been depicted as a friend and sometimes love interest of Clark.