https://wiki.project1999.com/Necromancer_efficiency and sort by mana efficiency, discount any dots you don't like (high fizzle mod, too slow, etc).
At 53 your best bet for dots: splurt, ebolt for dps/ignite blood for efficiency
paralyzing earth is your long root, root/hungry earth is your cheap bad root
I just use a cheap snare if I use snare at all. I charm solo so don't snare a whole lot, and have epic now so when I do I just click that.
Hardly an expert but the above works for rotting mobs left after charming through a pack