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.

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.