# Do powers/feats/features that buff a character's healing work with Skald's Aura?

Skald's Aura: [...] you or any ally in the aura can use a minor action to spend a healing surge and regain 1 d6 additional hit points. Alternatively, you or any ally can use a minor action to allow an adjacent ally to spend a healing surge and regain the additional hit points.

Is it correct that e.g. a fighter who heals himself using Skald's Aura gains no benefit from a Skald with any of these

Mark of Healing (feat): Whenever you use a healing power on an ally or use Heal to allow an ally to spend his or her second wind, that ally can also make a saving throw.

Healer's Brooch (item) Property: When you use a power that enables you or an ally to regain hit points, add the brooch’s enhancement bonus to the hit points gained.

Master Skald Level 16 (feature): Whenever you restore hit points to a creature with a healing power, the creature regains 4 additional hit points.

(and most others)? As far as I can tell, it has to be the Skald himself who actively performs the healing (standing adjacent to the recipient) in order for any of these types of effects to take place (making most of these choices a bit useless for the class).

The other two you mention are predicated on the healing keyword. Skald's Aura has this keyword so they both work.
The basic rule is to determine whether or not the power/feat/etc specifically mandates the healing keyword and whether or not the power/item/etc you are using contains that keyword. So, mark of healing requires a power to have that keyword, healer's brooch does not.