So much misinformation in OP post....

-Healing Modifiers do not provide extra threat to the healer.
-You wouldn't weave Vengeance for Wrath stack now with the 30% mitigation it's too valuable to use just for a Wrath stack.
-Storm Path just allows your bard to be lazy now than before. Other than that I will call it a nerf cause you will have trouble providing Storm Eye Debuff
-Holmgang good but effects may be negated as healers have to switch off heals to make this skill worthwhile for the 6 seconds it is active and then make sure you have enough HP after the 6 seconds.
-Convalescence opinion = /facepalm. Big heal numbers =/= more effective heals!
-I didn't read anything about Mantra being 20% let alone 30% in patch notes. It's current state only provides 5% healing increase.

Shield Oath and Defiance enmity was broken cause Enmity was tied to Damage done which was reduced just being in that stance. Things that aren't affected by damage done such as Overhealing with Cure/Flash still generate the intended amount of threat when performed by a tank.