I myself, when running full blood necro, have 15 in blood, 13 in soul reap, and 3 in protection prayers (for rebirth). i absolutely LOVE having my soul reap that high. I use wells a lot as a staple of my blood necro build. Well of Blood and Well of Power...when they overlap...10 (possibly 12) pips of health regen and 2 more pips of energy regen. Mmmmmm. Everyone i've partied with in pugs ends up loving My precious wells.
And as far as triggering soul reap, as far as ive noticed, anything within an eye's distance that is killed gets me my +13 energy. This includes party members, pets, ghostly heroes, minions, shadows...etc.
A good place to Test out your Soul Reaping Range is D'alessio Seaboard. Just head to the Mission Outpost and see what your max range is for your soul reap to be triggered. (The White Mantle are killing all those undead things outside)
Good luck
