Your request is rather broad. I don't even know where to start...
I have never seen that guide before and it has a LOT of useful information that is still relevant to SCH. However, there is one important topic that I noticed the guide does not address:
Utilizing Day/Weather Bonuses
I noticed that the guide does
not put Elemental Obis or Twilight Cape in their "Max Damage" equipment set for SCH.
Elemental Obis are definitely something that you need to get your hands on (I recommend at least
hyorin obi,
rairin obi,
korin obi, and
anrin obi) for proper Scholar nuking
and curing. These pieces of equipment can increase spell damage by percentage, which is a much more potent increase than what a few extra INT would provide.
For example, let's say you cast Firestorm on yourself and then cast Fire V (or any damaging Fire spell). Since the weather matches the spell, there is a roughly 33% chance that the weather will give your Fire V a bonus in damage. The same goes for the day; if you cast Stone V on Earthsday you have a 33% chance of getting a boost to the spell's power. Elemental Obis
guarantee that this bonus will occur
100% of the time. The specific bonus to spell potency are the following:
+10% for magic matching the day
+10% for magic matching single weather
+20% for magic matching single weather and day
+25% for magic matching double weather
+35% for magic matching double weather and day
In addition to obis, the
Twilight cape grants and additional +5% bonus to the regular weather/day bonuses in the list above as long as either the day
or weather match. However, please note that the Twilight cape does not guarantee the weather/day bonus will occur, it just increase the potency by +5%. For example, casting a Cure spell on Lightsday while wearing just a Twilight Cape will give you a 33% of getting a 15% (+10% from matching day, +5% from cape). However, if you equip a
korin obi and do the same thing, you will get +15% bonus
100% of the time.
Please note that obis (but
not the Twilight cape) also have the opposite effect on spells that are weak to the element. For example, wearing a Hyorin (Ice) Obi during double ice weather and casting a Wind spell will decrease the Wind spell's damage by 25%. Thus it's important to be mindful of the obi you have equipped. However, there are some instances where doing less damage can be useful (e.g. trying to get a yellow proc on weaker NMs in Abyssea).
Scholar as a Healing Job
I mention all of this because you asked the state of SCH as a healing job. As Niniann mentioned, SCH can now reach 50% cure potency through equipment. On top of this, SCH can also gain an additional +15-40% increase in potency to their cure spells while wearing the Twilight Cape and Korin Obi. While other jobs can wear the cape and obis and gain the same bonuses, they only benefit when it is Lightsday or when there is Light weather present (which is rare outside of Nyzul Isle or Limbus). This essentially means that our Cure IV is able to surpass that of a WHM by at least 15% since they cannot cast Aurorastorm on themselves as a WHM/SCH.
The recent boost to our Regen spells while under the effects of Light Arts is very exciting. Regen is very mana efficient, produces little enmity, and can help keep your party member's HP topped off so you can save your MP to heal the tank. I love to use Accession + Perpetuance (w/ AF3 hands +2 equipped) + Regen V. In a stable fight usually the tank is the only job to take damage. Occasionaly a mob or NM will use a AoE attack that damages nearby party members. If they have Regen V cast on them you usually don't need to bother throwing them a cure as there HP will top off on its own in a few seconds.
I would not argue against a -enmity set. It's no secret that Cure IV produces ridiculous amounts of enmity. The guide you linked goes pretty in-depth into the enmity produced by cure spells, so just use your own judgement. I personally prioritize cure potency, but have considered making a proper -enmity set for Campaign Battles.