Any healing potentially done with arcane would likely amount to using it to “mechanically” rebuild the wound. As the magic of Order, arcane magic is basically about “moving things around” to arrange them into new patterns, shapes and systems, while most other magics’ healing would arguably be along the lines of the energies in question strengthening the souls attachment to the body while fueling and greatly accelerating the body’s own inclinations to repair and heal itself. In theory all six magics can likely be used to facilitate bodily healing, but while some would themselves be the energetic catalyst, others would do so by taking life-giving energies from something else nearby and transferring them to the person in need of healing. So while the fel itself can’t heal, it can be utilized to steal life from another creature, then transfer that living energy to the injured person and heal them. Even Death magic can heal by way of anima existing as a transferable energy medium.
That said, for arcane to heal, the caster needn’t necessarily understand the physiology of the patient; the way it works, the more arcane energy one uses, the more the magic itself starts “doing the math for you” so to speak, which is why after Aegwynn was granted the Guardian power, she found herself able to toss off spells with just a thought that used to require extensive rituals, runework and incantation before.
The addiction of the arcane is tricky; it used to be outright described as such across the board, but for a while now literal physiological addiction has become pretty specific to elves. Other races can become psychologically addicted to the power, as one can with any power if you become too used to always having it, but a biological dependency that causes physical degeneration when deprived is only really shown in elves. Possibly because their nature as elves in the first place came from long-term exposure to arcane energy from the Well of Eternity, which may have basically made their Ordered physical forms and functions reliant upon the energy’s proximity to keep them that way unless something is used to stabilize the energy, and therefore them (see: moonwells and the Arcan’dor.)
While it’s not made available to players, the ability to increase one’s physical strength, resilience and durability with arcane magic seems likely; “warmages” and “battlemages” with what amount to “warrior” weapons and armor for close fighting exist in-game as NPC’s, so while the game balance as it exists necessitates that a player mage not be able to double as a tank while dealing heavy magical damage, in-lore there doesn’t seem to be a hard limit on the idea of magic-users utilizing the arcane to modify their physical combat capabilities.