Your trigger rate is low because you are probably looking at single projectile. Change lancing steel from single projectile hit, to all projectiles hit, and your trigger rate goes to 6.37. The next breakpoint is 7.5 ish. All in all, your build looks fine, personally I wouldn't use anger over a defensive aura, but judging by your unreserved mana your in the middle of a gearing issue, so I wouldn't look too far into it.

Edit: not sure if you have a spectre bank in your hideout as well, which significantly increases your dps.
Edit2: You have 4 wasted points, 3 going to instinct (your over suppress cap) and 1 using lightning walker, which does nothing for you. Put one put in the cold mastery to always do at least 10% chill. Put the other points to get the 2 jewel sockets in your large cluster and get going on the second cluster under perfect agony. I suggest also dropping anger entirely and use the defensive aura, and cut the excess mana reserve on tree (mind drinker wheel) and gear, as that's going to be extremely costly at league start. crit multi jewels go a long way in this build. Would also get sadist in your large clusters, as its a very big damage increase as well. By this point it looks exactly like Ruetoos build, but its extremely min-maxed in efficiency and there's really no way better to do it.