Dust Blast is marked on this page as 2 Geomancer and 2 Necromancer. It's 2 Geomancer and 2 Huntsman.

i do not recommend these. enemy's resist is so high

Best paired with fire mage, tank, and rogues.

Cannot Stress enough how useful some of the level 1 skills are in this tree. Fortify alone is a worthwhile skill on almost any character for your early and midgame and dust throw on any character even a non archer can be a life saver. My rogue if you can even call him that anymore (Scoundrel, Necro) even has some gemomancer skills just for the utility.

Reactive Armour has to be updated. 2 AP, 6 CD.

2 points in Geo are still a must have on any physical melee character.

Worm tremor doesn't appear to function properly
Characters can still move with it applied, albeit at a massively reduced pace, and can teleport themselves with movement skills
For example, a fighter could phonix dive, a rogue could backlash etc
It seems to block other characters from teleporting them which IS NOT GOOD, since they can still teleport themselves; it means you as a caster lose a major control skill for a movement slow and some ongoing poison damage
It costs 3 AP too, so it should actually stop them from using teleport attacks given how much AP it costs

Some of the spells seem to work differently from the description of the spell. Impalememt: says Resisted by Physical Armour but actually deals Magical damage.

Nope, it is correct. It deals Earth damage, but crippled checks for physical armor. So, someone with physical armor will never be crippled by using this skill, since it does not reduce the physical armor (magic [earth] damage after all)

I dont have to remind not to focus on poison skills because of so many enemies with high resistance to it, besides the undead you often come across. Earth is good though.