[3.10] Rain of Arrows Doomfletch Prism Build (First Build - Newbie)

Hi,
This is my first attempt at creating my own build in standard.
I wanted to make a Doomfletch rain of arrows build. Any help would be greatly appreciated. I have chosen a Trickster as Harness the Void & Swift Killer provide significant increases in damage output.
I'm currently do Tier 10 maps reasonably well. I would greatly appreciate some tips on improving the build

Gem Setup
Rain of Arrows - Vicious Projectiles - elemental damage - mirage archer- chance to bleed - concentrated effect

Defensive
Cast when damage taken - Immortal Call
Cast when damage taken - Steelskin - (also linked with projectile weakness)

Movement
Dash - Second Wind

Auras
Herald of Purity (added physical scales like crazy with the build)
Arctic Armour (I have been using this due to some large physical hits getting very close to one shotting me, not sure if I need it anymore with the extra life nodes I have picked up
Herald of Ash or Ice replacing Arctic Armour???

Path of Building Link
https://pastebin.com/d0wU7cwH

To do list for build next few weeks
1) Finish ascendancy to get ghost dance & escape artist
2) upgrade rings, gloves, quiver, flasks

Questions
1) How much life do I need with a essentially an evasion build with CWDT - immortal call / Steelskin
2) Is my single target damage with rain of arrows high enough to effectively do late game bosses?
3) Advice on Jewels to use and should i take passive tree jewel sockets?
4) Advice on passive tree in general?
5) other advice of stuff i haven't thought of?


Current Setup



Thankyou in advance for your help