I main Ele and have mostly played support tempest for many seasons now. I'm upper P1 mostly.
I haven't tried this build, but it seems to offer a good amount of healing. The range of staff would definitely help in surviving but I'm not sure if the trade-offs are worth it; will have to try it first-hand. It's more oriented towards direct support to allies than its Thermal Cleansing counterpart. However, I prefer would Thermal Cleansing still (with dagger/focus) because it offers greater offense, which allows me to mitigate damage to my allies in fights while actually helping get enemies downed. There are loads of Heal Guards running around these days, and having two direct ally support classes is not good. Moreover, conditions on allies are never a problem as I have "burst aura" skills on Fire and Air, each removing 2 condis, in addition to 1 being removed with every aura shared. Since I have 2 sources of projectile reflect on weapon skills, I can replace "Aftershock!" with Conjure Shield, which is generally a better utility (with magnetic aura in it), or Mistform, for the much needed invulnerability needed on this squishy build when being focused. Focus Earth 5 also gives invulnerability.
Tornado over Glyph of Elementals, great source of multiple AOE CCs, again for more offense and prevent enemy revives - turns the tide of a fight. Yes, Water Elemental's AOE healing skill is very strong, but attacks are melee, which makes it vulnerable to dying potentially pretty quickly in team fights from AOE dmg.