Excellent questions.
#1- Um, YES. Dungeon of Doom is WAY scarier than the MAUSOLEUM.

the Maus on the scare factor is a 5 1/2 out of 10 and the dungeon of doom is a 9/10.
#2- The buried alive protion is the last section in the HH. What happens is you go inside and they tell you to sit in these chairs. You know those McDonalds play place balls? All they do is paint them brown and burry you in those.