In some comic arcs, Mystique has met her demise. However, comic universes can be complex and her fate can vary depending on different storylines and reboots.
It depends on which specific comic book arc you're referring to. In some, she meets her demise, while in others, she survives and continues to play a role.
Well, Mystique's age isn't precisely set. It changes based on comic book reboots and alternate timelines. Generally, though, she's been around for a long time, having been involved in many significant events throughout comic history.
Sometimes. It depends on the specific comic arc and the context. In certain situations, Mystique's actions might be driven by motives that could be seen as somewhat good, but her character is complex and often morally ambiguous.