That stilleto gets too much praise for what it is worth. You are doing 101-104 damage which is then subtracted by ~75, which leaves you doing 25 damage per hit. While using a weapon such as a strength level 55 sword you will be doing about 200 damage per hit -75 = 125 damage. Do a critical hit and do 250+ damage. IMO daggers should never be used.

I usually will use my tanking gear for mobs, and if there is another tank I will switch to my dex set once we get to the boss.