bow kiting mechanics/question

[Tann]

Plenty of comments on ranger peeping with a bow not being a super viable way to exp but I'm curious just how "bad" is it?

Having just leveled a druid up with a lumi staff and by the low 50's seeing the mobs health drop by 3-5% every 20ish seconds I'm wondering is that kind of slow or way worse? granted i'm quadding but still..

Also, a mechanics question:
Given the double damage to stationary non rooted targets at 51+, is that literally the only scenario this functions or are there other situations where its double damage? like fear kiting? unsnared mob fleeing at low health? blinded by a WESS, snared, and out of melee so pathing around aimlessly?