5) If the spell ends prematurely (due to a dispel, for example), then the the character's consequences revert to whatever they would have been if normal healing had occurred.

For example, a character takes a mild, moderate, and serious consequence.  A Sidhe generously casts a spell to grant him Supernatural Recovery ... for a consideration to be determined later.

Normal healing would have resulted in the mild disappearing after one full scene (about an hour), the moderate disappearing about a full session (a few days), and the serious drops off after a full scenario (about a month).  Supernatural Recovery would result in the mild disappearing immediately and the moderate disappearing before the next scene (15 minutes?), with the serious lasting merely a full scene (about an hour).  The Fae needs to cast the spell to last the full month, and the healed character gains the benefits of that healing as if he had the Recovery power.  However, if an ebil Sorcerer detects the spell and dispels it during the next session (or a week later), then the player gets the serious consequence back (with a session or a week credited toward recovery).  The mild and moderate stay healed, since they would have healed by then anyway.

2) Allow limited healing along the lines of allowing a wound to be reduced by one level (per the Reiki Healing spell on YS300 which contradicts what is stated on YS284).

4) Allow healing by way of thaumaturgy-generated 'borrowing' of a Recovery power (per the temporary power rules).

Armor of Faith [-1]
Description: Your faith is a tangible and potent shield against the attacks of the supernatural, enabling you to blunt or even negate the attacks of your foes.
Musts: You must have taken Righteousness (below) in order to take this ability.
Skills Affected: Conviction.
Effects:
Armor of Faith. Your faith is a tangible force that protects you from harm. You can use Conviction to defend against physical attacks (page 200) and to perform Blocks (page 210) in physical combat.

Blessing of Faith. Your are imbued with the power of faith and can be used to hearten your companions. You can use Conviction to perform maneuvers that grant minor blessings (as temporary aspects) upon your allies. All aspects granted with this power must be tied to your faith and may never be invoked to aid actions that are anathema to your faith.

Faith Healing. Your very touch can ease the wounds of your companions. You may use your Conviction skill to declare justification for your own or another character’s recovery from moderate or severe consequences of any type, even without access to proper facilities, given time to pray and (for another character) lay hands upon the character in question. In addition, you may spend a Fate Point to allow another character to heal from a Consequence as though it were one level lower in severity. So, the subject would recover from moderate consequences as though they were mild, etc. Consequences reduced below mild are always removed by the beginning of a subsequent scene.

The idea is this character began studying magic at a very young age, though he doesn't have the power of a full wizard. At some point he confronts some Red Court Vampires, who infect him. Someone (or something) powerful intervenes and morphs him into something similar but different. Where a vampire draws power from the demon that sets up shop in their body, he draws his power from a spirit of light with limitations similar to a half-vampire.

And like GryMor said, without some casting power, you have no way of boosting their power in any way, which can be a huge disadvantage.

As an upgrade, the character got Modular Abilities linked to an item of power (or in this case a collection of items of power), to offset the 2 refresh charge for being able to change his powers. So he has a [-1] "collection of magic artifacts", which allows him to take up any (well, within reason and if the GM, me, agrees) power worth 1 refresh. So far, it has been used for a magnifying glass with the Psychometry power and a phoenix shell amulet with supernatural recovery (the catch brought it down to a cost of 1 refresh) to safe an npc from dying.

I've got a character like that in a campaign I'm running, and we are started modeling this with refinement. The character takes refinement for the enchanted item slots (4 slots per refresh spent), and their power is based on his contacts skill instead of lore (without a stunt). They can model a wide range of effects, though some limits can be enforced by compelling the corresponding aspect.