What are you running for defenses? Decoy Totem, man, Decoy Totem. And I don't think I could survive without a CWDT setup on a caster. Eww. On a summoner, my preference is for CWDT + Tempest Shield + Arctic Breath + IC. But you could do without the Arctic Breath and throw it on a weapon/shield, if you just don't have the 4L space.
I realized that I had totally overlooked two incredibly important thing on my Inquisitor: Ghost Reaver (Leech goes to Energy Shield instead of Life) and dropping Clarity for Arctic Armour. Those two together have made a significant improvement to my tankability.
FWIW, also, I really dislike the 2.6 life/ES tree in the guide I got the basic idea from. It goes down to the Wheel o' Life, but wastes like 8 travel nodes to get there. Sad! Much better to pick up the excellent life clusters like Purity of Flesh and whatnot that are much closer.
Feeling pretty happy with my tree at this point. I'm at the point where I'm smooshing low-tier maps and just kinda waiting/grinding for better map drops to push deeper into the Atlas.