Something that I think would make an auramancer more useful is the ability to pass on an aura, for a period of time, and then project another one.

For Example, if you have a regenerative aura, pass it on to a frontliner for something like 3+Con Mod rounds and begin a new aura, let's say an aura of protection, as a free action. I mean pass it and start a new one all as a single free action.

Another thing would be using auras offensively, like a debilitating aura or an aura of sickness. Being able to pass that on to a melee character while you use a beneficial aura would be better I think.

I guess that if Auras are going to be the focus of a class, they really need to function more like spells or encounter based class features. Possibly something like the Chanter from Pillars of Eternity? You chant and create auras that persist for the whole time you're chanting that particular chant.

If we're going with a more Chanter stylized auramancer, it would be important to set a clear progression. Start with a number of Phrases known which take a free action to say and grant a minor bonus. At say level 3, if you combine 3 phrases together into a stanza as a standard action you create a combination of their effects and they are enhanced. At level 6, if you take a full round action to combine 3 stanzas into a chant, it produces a combination of those effects that are also enhanced. At level 9 if you take a 1 round action (so you start it on your turn and then it takes effect at the start of your next turn) you can combine 2 chants into an epic which is essentially your class capstone at level 9. Continuing to progress in the class would grant access to higher level, more powerful phrases. The key to making this work would be by making the phrases vary, such as some that cause damage, some that heal or restore, some that protecte physically, some that disrupt, and some that debuff. For instance:
- Level 1 Phrases: Bare your teeth (+1 to attack), Ready your shield (+1 AC), Staunch the Flow (Fast Healing 1), Terrorize the soul (Shaken, Will Negates DC Cha based), Slice the flesh (1d4 damage, Will 1/2 DC Cha based)
Then, at level 3 you can combine Bare your Teeth, ready your shield, and staunch the flow into an aura that provides +2 attack, +2 AC, and Fast Healing 2 (or something like that) for as long as you maintain it, which would be a standard action at that point.

Something like that would be a good auramancer I think. Passive abilities are rarely good as primary class features and changing them to something that can be shaped, molded, or customized would be important for increasing how valuable auramancers are as a class.