Sakura's mom isn't winning this one. Kakashi became a Chuunin at 6 and Jonin at 12, and he's a veteran of the last war when he was just a kid. He's an absolute gentleman. There are very few in the world more fit for her than him lol. The subject of his possible death does seem like it would be raised regardless of his background though, but that's the life they both chose. Only person who can kill him is Tsunade by overworking him with missions to keep him and Sakura apart.