When I was levelling my thief and developing skills I found the skill "caltrops" useful in taking on groups. it cripples and bleeds them and combined with SB a group goes down fast. If you get caught you more than likely get a rally off them. I dont use caltrops much now but when getting skilled with the SB it helped.
I didnt find the norns or charrs a problem. At the beginning you just felt your way with the jumps I jumped many times without really seeing my myself, after a very short while there was only 2 to 3 of left . A great puzzle , great design and very rewarding to finish, even without the chest. I love the way they have given us a timed puzzle that demands speed, skill and perfection over 60 to 90 secs.
More please ANET.
(I found using both mouse buttons for run / direction best, rather than keys.)
I just did this after 90 mins and probably near 100 attempts. I feel just absolutely great, the relief of getting to the end is so palpable its unreal. Its a real test of timing, nerve and skill. Thanks ANET.