Answered Light fury and life/mana leech?

Yes and no.

You won't get apeshit-leech from your fury hitting 50 cows 3 times each because you only leech off of physical damage and not off of elemental damage.

All of those throwing skills however (much like charged strike) come with a physical component which is the actual javelin being thrown (before it shatters into the lightning stuff). That physical component will give you life/mana leech much like any other physical attack would. That's why eth titans are so much better than normal ones, even for a pure fury zon, because it basically gives you 50% more leech due to the increased physical projectile damage.

Do note that the physical component is subject to normal hit rules however so even though the lightning sparks always hit, the physical projectile can actually miss due to low AR and such. It can also pierce and hit more than one target (in a line) however, resulting in multiple leech hits.