I am playing a Shockwave Totem Warrior

How to I prevent interruption by enemies when trying to cast the totem? They also interrupt rolling slam which is annoying. Do I need more armor or what?

Totem placement speed, grab some on the passive it will make the build feel significantly better.

Use a shield, and use shield charge to move around.

The most important stat on your gear is plus levels to melee skills above all else. Dmg on the weapon doesnt matter.