As I recall, THM and ACN both use one's internal aetheric reservoir to power their spells, which is why you have that whole arc in the THM questline about the one Coco brother whose natural aether reserves are so small as to be unusable. This is different from using one's actual life energy (the aether that's keeping you alive) like the girl from the Conjurer questline is doing. Continuing along that line, Conjurer pulls its aether from the Elementals - the only non-job class with external aether sources.
When you get into the jobs, things get mixed up some. White Magic and Black Magic are so dangerous because they draw their power from an extraneous source - specifically the planet. The War of the Magi was such a dangerous thing no just because they were throwing huge, powerful spells and killing people... but they were effectively killing the planet to do it. Which is why the Elementals flooded Hydaelyn, restricted White Magic to just the Padjals, and Black Magic is generally considered to be A Very Bad Thing. Astrologists apparently draw their aether from specific constellations, so they also pull from an external aetheric source, leaving SCH/SMN as the only ones that still do big things using just their own aether (even if SMN take in some primal aether to be able to summon egis).
Moving away from the aetheric source for magic a bit, focii are actually relatively important for spellcasting. The gem in a THM's rod, the wood in a CNJ's staff, and the metals used in the ink of a ACN's formulae are all exactly that - a focus. By using them to cast spells, you focus and amplify the power of your spell to make it that much stronger. The better the material at conducting and amplifying magic, the greater resulting power of a spell. A THM's Fire I spell will do more damage with a high-end rod than Mage's First Stick. Whether or not one can cast a spell at all without such a focus is uncertain, but a few folks have RPed as being able to cast more wild, unfocused and lower-powered spells without the required weapon handy.
So, I'd agree that the power of one's spells would be dependent on most of the factors the OP mentioned. Knowledge isn't just knowledge of the spell - but also knowledge of pulling aether from external sources in the case of White and Black Magic to further boost your spells. Which leads into Aether Source, which can be how much is in one's natural aetheric reserves if they are not pulling from an external source. And finally, the quality of one's weapon and the materials in its construction aid in the focus and amplification of the spell to maximize its potential.
I would put little stock in School of Magic, since as we have seen, all of them seem to (mechanically at least) be able to do Big, Dangerous Spells. The only difference is with Black Magic, which is technically not a school of magic at all, but a technique. There is available lore attesting to the great things Black Mages have done with the power they've taken from the planet - moving mountains and calling down stars. Even the other offensive casting class - the Summoner - mostly relies on their own aether and remnants of fallen primals. Comparatively, THM is the "most powerful" school since Black Magic can be used to bolster its power to awe-inspiring heights.
When you get into the jobs, things get mixed up some. White Magic and Black Magic are so dangerous because they draw their power from an extraneous source - specifically the planet. The War of the Magi was such a dangerous thing no just because they were throwing huge, powerful spells and killing people... but they were effectively killing the planet to do it. Which is why the Elementals flooded Hydaelyn, restricted White Magic to just the Padjals, and Black Magic is generally considered to be A Very Bad Thing. Astrologists apparently draw their aether from specific constellations, so they also pull from an external aetheric source, leaving SCH/SMN as the only ones that still do big things using just their own aether (even if SMN take in some primal aether to be able to summon egis).
Moving away from the aetheric source for magic a bit, focii are actually relatively important for spellcasting. The gem in a THM's rod, the wood in a CNJ's staff, and the metals used in the ink of a ACN's formulae are all exactly that - a focus. By using them to cast spells, you focus and amplify the power of your spell to make it that much stronger. The better the material at conducting and amplifying magic, the greater resulting power of a spell. A THM's Fire I spell will do more damage with a high-end rod than Mage's First Stick. Whether or not one can cast a spell at all without such a focus is uncertain, but a few folks have RPed as being able to cast more wild, unfocused and lower-powered spells without the required weapon handy.
So, I'd agree that the power of one's spells would be dependent on most of the factors the OP mentioned. Knowledge isn't just knowledge of the spell - but also knowledge of pulling aether from external sources in the case of White and Black Magic to further boost your spells. Which leads into Aether Source, which can be how much is in one's natural aetheric reserves if they are not pulling from an external source. And finally, the quality of one's weapon and the materials in its construction aid in the focus and amplification of the spell to maximize its potential.
I would put little stock in School of Magic, since as we have seen, all of them seem to (mechanically at least) be able to do Big, Dangerous Spells. The only difference is with Black Magic, which is technically not a school of magic at all, but a technique. There is available lore attesting to the great things Black Mages have done with the power they've taken from the planet - moving mountains and calling down stars. Even the other offensive casting class - the Summoner - mostly relies on their own aether and remnants of fallen primals. Comparatively, THM is the "most powerful" school since Black Magic can be used to bolster its power to awe-inspiring heights.
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