General's Cry Champion - Help configuring PoB & how to improve.

Fellow exiles,

I'm currently playing a General's Cry Champion, using Lacerate of Butchering. I'm doing impale and trying to go crit aswell. Here's a PoB configured on the low side.

First, PoB config. I can have 6 mirages. Should i tick 6 times Lacerate of Butchering and look at full dps ? Or do PoB automatically takes into account the max number of mirages in the combined dps section ?

Second, differences with the video that presented the build from last league. In the video i watched, the dude used the fourth vow along a timeless jewel to convert damage taken and it looked like it gave him a lot of tankyness (divine flesh iirc). And then he could scale his damage hard using the scream of dessicated belt (diamond version, so crit capped from the belt alone).
I'm trying to invest into crit using the second sight keystone (25% more melee crit chance) from Nasima's timeless jewel instead, but i'm losing a lot in ehp and max hit. Looking at Forth Vow & Divine Flesh gives me the feeling that i'll be closer to zdps than anything.

So third, how to improve the build overall ? Where and how to improve tankyness ? And dps ? The buid is fast enough and has explosions (devastator notable from large cluster), it feels good enough for mapping to me. The single target looks fine but not uber territory (let alone tankyness). Also, I'm getting murdered by dots.

Hope its clear, bit of a text wall, sorry. Thanks in advance !