I just recently had an incident where a number of npcs in Whiterun were killed and I couldn't do anything about it.

I still think however that such an amulet isn't needed on the consoles. Why? Because the incident was purely my fault.
The method I used that took me to level 14 gimped me, so I couldn't do a damn thing about the attack. Had I leveled my appropriate combat skills (magic) I would have been able to better defend the city and possibly save those NPCs.
Inconvenient? Sure.
Frustrating? Certainly.
Exhilarating? Abso-friggin-lutely!
This is my first experience of a vampire attack on this level, where I was completely helpless to stop it. That's some good writing and great drama, and for it to happen so spontaneously

, it's awesome!
Personal feelings aside, I stand with those who say "
by now you should know what you're getting into" so if it's become a big problem for you then delete the content until you're at a high enough level to be able to properly deal with it. My first exposure to Dawnguard was with a level 38 assassin, and she was more than capable at handling the attacks. Daedric Weapons and Serana (or a competent follower) also help

.
I have also learned by now that with anything
new and unknown in Skyrim you should
always always always save save save at nearly every moment.
- Character level suddenly? Save.
- Skill level? Save.
- Come to a dungeon door you know you're going to load through? Save.
- Finish loading through that door? Save.
- Scraqe by in a fight? Save.
- Fast travel? Save before and after.
Following this advice I could have easily reloaded because I saved before I fast-traveled to the stables.

I don't see an issue here.