Anomalous Detonate Dead CwC Corpsewalker - a PoB and some questions on mechanics

After toying around with various DD options, I've stumbled upon Noteworthy Interactions #8 and used some of the ideas as a foundation for a Necro I've been leveling. I'm pretty happy with the result, but there are some gaps I'd like to close.

https://pastebin.com/w8qFVi6Z (this is more or less the current state of my build, not a fully optimized version, which would probably include indancesent heart and 20/20 gems as well as some gem upgrades, i.e. awakened supports and alt quality withering step).

Some key ideas of the build:

• Full Fire to chaos conversion using Anomalous DD and Ashes of the Stars
• Chance to poison at 100% using Divergent Herald of Agony (with a circle of Nostalgia) and Ashes of the Stars
• Scale damage off Wither effect and Corpse Life
• High Block chance thanks to lvl 20 cwdt Bone Offering
• Very good ES recovery/mitigation thanks to Aegis Aurora, high Armour and Divine Shield & 10k Mollten Shell temp HP
• Good automation thanks to CwC and Corpse Walker
• Not very zoomy, but my focus is on tanky boss performance.

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These are my questions regarding conversion and DD & spectres:

1. When converting elemental damage to chaos damage, will the "increased elemental damage" mods also apply to the poison damage?
2. It looks like Void Manipulation is slightly better than Elemental Focus Support. This is probably only due to the added Chaos damage from the ring, correct?
3. Are there any obvious optmizations in the tree pathing, in regards to dps?
4. The weapon slot is very flexible, I've gone for an ele damage sceptre. If there are other viable weapon choices (Dark Seer was looking interesting too), please let me know.
5. What should I do with my spectres? It looks like they die a lot anyway. Can I just keep an unsupported spectre gem to make sure there's a chance of spawning corpses from my spectres? Do I need to have an active spectre at the start of the map to get its corpse to spawn?
6. Which are the right spectres and how many past spectres are "remembered" by Corpse walk?
7. How do I set up PoB correctly that I'll get a realistic dps estimation? (In particular, what do I put in for corpse life?)
8. Once PoB is set up properly, which of the Dot related anoints do I take? Or do I just go with sanctuary? (I just realized that pathing to Santurary, unspeccing off the Atrophy, but picking up Brutal Blade is only a slight dip in DPS, but ends up at 75/71 block chance and a lot of resists.)
9. Any ideas on how to cap the block chance? I'm at 68/65 with bone offering & full endurance charges, which is already pretty good, but getting to cap would be nice.
10. The Megalomaniac is a kind of place holder - if you can think of other interesting cluster jewel notables worth including, please let me know.

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