Hello!,
1. Yes, you have to roll a dice to Wound and if is successful, target have to save with -5 rend modifier ...the Wound always is done with this modifier
2. Y like Terrornight Venom, Arcane Pearl or Sands Of Infinity
3. If you like an eels list, you can use all you want...Leviadon add cover, and melee attack and makes the opponent focus a lot on him..it is a good option.