Just me or does the Resto Shaman build seem rather...dry?

I'm looking at the WoW book on how to play a Resto Shaman, and it basically says play a World Tree Barbarian. While this provides a strong buff in the way of single-target Temp HP, it provides no other healing. I've got some ideas, but I'm still working them out. For starters...
Replace Vitality of the Tree with Living Waters.

Level 3: Living Waters
Healing Rush: Providing healing or temporary hit points extends you Rage by one turn.
Healing Wave: Once per turn, while your Rage is active, you may use the Magic action to heal a creature within 30 feet. To determine the amount of healing, roll a number of d6s equal to your Rage Damage bonus, and add them together along with your Wisdom Modifier.

This seems to balance by requiring an action, but giving a 30' range and converting THP to healing. I'm still working on how to incorporate Chain Heal and Healing Rain for the higher level features. I'm thinking about expending a use of Rage as a Magic action, but still working on when and how to avoid making them OP.

EDITS for additional features...

Level 6: Chain Heal
Chain Heal: Expend 1 use of Rage as a Magic action to create a stream of living water that Heal the friendly target, then jumps up to 20 feet to heal the next 2 most injured nearby allies. Healing is reduced by 1/3 of the original target with each jump. To determine the initial heal, roll d6s for each Rage Damage dice, add them together and add your WIS modifier.

Level 10: Ancestral Toughness
Ancestral Toughness: When applying Healing Wave, you may choose to grant your target Ancestral Toughness, giving them an AC bonus equal to your Rage Damage bonus. Only one target may have this bonus at any given time and the effect ends when your rage ends. You may do this a number of times per Short Rest equal to you uses of Rage.

Level 14: Healing Rain
Healing Rain: While raging, the Shaman may expend 1 use of Rage as a Magic action to create an immoveable 10-foot radius cylinder of living rain within 30 feet of the Shaman. Allies standing in the area gain temporary hit points equal to a number of d4s equal to the Shaman's Rage Damage at the start of their turn, lasting for one turn. The rain continues while the Shaman maintains rage.

Any thoughts on the edits?

Healing Wave seems rather broken. Rage lasts for up to 10 minutes, so at 3rd level, you could restore about 850 hit points to the entire party.

Not being able to provide unlimited healing is a core principle of D&D; any healing should require expending a resource, not just an action. That resource could be a rage, however.

My thought was that straight healing is slightly less beneficial than THP, since THP can be given ahead of damage and prevents overhealing. It does add the WIS modifier, but other than that provides the same amount of HP as Vitality of the Tree. The main difference is making it use an action and giving it more range.

I thought I added this to my original reply, but...
Vitality of the World Tree at 3rd level, as written, is essentially like casting Power Word: Shield on the Fighter for 30% of his HP, every turn, for free. That is a bit OP at low levels, but that's what my Healing Rain was based on. It doesn't scale as well, being about 15% at level 20.