When you sneak and put a live frag grenade on somebody is it always an automatic kill no matter what? Also, is doing this successfully influenced by sneak or explosives skill or both? And can any other explosive weapons do this?

I,m fairly sure the sneak skill influences this.Also you should be able to do this with land mines as well.

yeah, if you got a sneak skill of 100 and an explosives skill of 5 you can still kill a Brotherhood Paladin with a grenade and some ham

Sneak determines if you are going to successfully put the grenade in their pocket.

Explosives skill has more to do with how far you can throw the thing. The blast damage maybe increased if you have a higher explosives skill, but a grenade in the pocket is still a kill at a low explosives skill.

:cookie:

A successful reverse-pickpocket of a mine or grenade is a guaranteed kill in all cases; doesn't matter how much health or DT the target has. Pulse grenades are a good choice for this as they won't do you much damage if you get caught in the blast.