hmm dropping a villager on a dead body will get you some interesting responses from the one dropped - usually will see their action as "Embracing" then see at the bottom of screen "THAT VILLAGER IS DEAD!!"
Some people have reported that when they drop a villager on a dead body that the dropee tries to heal them. I usually take my seniors and pick them up and put them to food bin to keep from watching them walk so painfully across the screen to bury a body - let the youngsters bury bodies.

On the missing bodies - I have noticed if you dont let the villagers carrying bodies get at least half way to the graveyard, then the headstone wont come up and the body they are carrying kinda "disengrates"