Study of the support gems for Poison

I'm still learning of poison mechanism, confused most time, so here is a topic:

well first there are some skills we all used for Pathfinder poison build:

1. PoisonBurst Arrow, main hand skill for clearing.
2. Gas Arrow, for aoe mass killing like Ritual-in-map or Delirium-endgame, also poison source for Toxic Growth.
3. Toxic Growth, for huge damage to kill Boss.
4. Vine Arrow, for slowing enemies, not vey much used.
5. Herald of Plague, for spreading the poison damage from PoisonBurst Arrow.

And here are some support gems I want to talk about:

1. PoisonIII, no need for the skills above IMO unless you play Bleed for the same time.

2. Deadly PoisonII, only need for PoisonBurst Arrow because of the poison damage to spread by HoP, I've seen lots BD using it on Gas Arrow and Toxic Growth, well for Gas it could add some damage but I would put other support gems for mechanism, and for Toxic Growth I think no need because we only need huge explosion damage.

3. Bursting Plague, no need because we have poison burst already and it's making more damage.

4. Tacati's Ire, only good for PoisonBusrt Arrow for faster poison DoT.

5. Arakaali's Lust, good for PoisonBurst Arrow for clearing or Toxic Groth for bossing.

6. Corrosion and Uul-Netol's Embrace are good for armour breaking BD.

7. Admixture and BleedIII for bleeding BD.

well that's all I can think of.