It's a pretty sweet little adventure, just a couple things that should be clear -- ran this with a party of 2nd level adv. The burrowing dead are quite nasty with being able to instantly cause death saves by suffocation. Be aware that with a couple good rolls, the party can basically die in the graveyard.
The Vardoger -- This creature is pretty awesome, but I'd advise one change -- the confusion ability should be much, much more limited. Rather than confusing save ends, it should confuse until the end of the hero's next turn. And really the confuse should be triggered off a high roll from another attack. It's just too powerful as an at-will, especially when you have a barbarian in the party - near insta-kills with his critical hits.
Also, the magic item is kinda neat with a great story and all, but its ability is laughable when most of the monsters instantly die from a critical hit in this fight. I'd suggest maybe saying that a critical hit allows a recovery, or removes conditions, etc...