It means, if I die, my best friend is going to kill you. You will not move on and start a new life without me.

I'm in that top categorie, but I must admit that I regret my vows.
Life is an awfully long time and people change.
It's hard work and even if it's successful, no one can stay in love for a lifetime.
It's just not possible.
In the end, it's about becoming each other's best friend.

I don't believe in divorce and I'll make that clear to the person I marry. I'm marrying them because I love them and I'll always work on our love together there's no exit routs.

Scariest line in the vows

These need altering. Because if my relationship is unhealthy I'm leaving.
Especially if I've done all I can to fix it.

It means until death do us part. If a person doesn't understand that meaning then perhaps they shouldn't be considering marriage in the first place.

Does it mean I have to shoot them? Asking for a friend.

What it says.

once someone dies it's over.