Agree more with the idea of increasing the "Adventurer in Need" bonus. It's not an elegant solution, but I'd like to see a tier of bonuses -- tier 1 gets more of a bonus than tier 2. Yeah, that will pretty obviously work out to rewarding tanks more than healers, but at least healers will get something.

Honestly, playing a tank is not that fun right now. I see no issue with giving them more incentive.

(But also: yes to healer mounts. Something more than a unicorn would be nice!)