How essential is Remains of Sahlahja?

How much of the Dynastic Tombs are needed for 100% completion? I am struggling getting any of the areas opened. The second maddened spirit spawns before I can get the second greater infestation killed =/. Can I get 100% without going beyond the initial area?

EDIT: I managed to get two maddened spirits killed and each time it opened a different area, so I now have GMC Elona. I was able to get the 100% with only a cursory wall scrape and not even having to finish the fourth quadrant, for anyone else with this question. Make good use of the Junundu Tunnel so you don't get caught before exploring the whole quadrant.

Read the sticky already? There is a guide which should tell you enough to be able to do it without much problems:
http://www.guildwarsguru.com/forum/s...php?t=10074308