Good and interesting i visions of things
As concerning the holy skill that heals you 100% of your hp you are the only heal to do that, it might be pleasent to play around that, if you get os, this mean you still have stuff to work on (Gears, resistance, hp and other)
For me LW is not a healer but more a buffer that is supposed to give the advantages against the ennemy team (in pvp) by making a lot of buffs, removing chances to get the "important" buff debuffed, and give a tiny bit of stats bonus against the ennemy team
in my oppinions it's more the buff that should be buffed, more than the heals, when geared you will see that you wont get os, and able to make proc your 100% heal way more often than if you get os (and that's normal)
I may be wrong , but that's a good thing! thanks !