1. Damage type. I think it should be poison. This is for additional synergy with the damage reduction passive. It would be great for tank docta's and additional group synergy at that point. Granted their are other options for applying the passive effect, just think this would be very efficient and get around some of the mana/range/AOE limitations that other spells have.
2. On hit effects: If damage is poison, reduce total % damage by leaping spiders and let allow one tic (very short DOT). Let that tic proc on hit effects such that the on hit effects don't stack to some ridiculous measure. Either that, or divide on hit effects by some number to balance with other attacks. Currently leaping spiders becomes useless vs. dmg reflect mobs because of this, even though the Jar can proc the effect. Once you get to act III inferno maintaining this as a main attack becomes nearly impossible imo.
3. Allow spiders to hit certain enemies and structures that they currently don't. Namely Belial, but also certain structures that require damage that aren't enemies. It is a pain to have to wear down a structure with grasp of the dead if you spec spiders + full crowd control.
4. Dampen the jar break sound effect. Please. With fast attack speed It's almost as annoying as the toad hemorrhoid scream.
I like the spell and will keep on using it. It and Toads are the most unique main attack spells we have in my opinion. Slight modification could make leaping spiders amazing, but I don't think the modifications listed would make it unreasonably amazing. Just my two cents.
What do you guys think?