I guess I'll toss out a few enhancing ideas, since that was also mentioned in the manifesto.
I suspect these concepts have been mentioned by somebody already, since they are far from inventive.
Wall - White Magic - Enhancing Magic: Would provide 10%-25% -Physical Damage Taken depending on skill level.
Barrier - White Magic - Enhancing Magic: Would provide 10%-25% -Magical Damage Taken depending on skill level.
Single target, immune to the scholarly wiles of Ascension, one would overwrite the other. Going right past the -50% cap would be pretty nuts, so maybe it could be a separate value so a bro or bro-ette with -50% Damage Taken would end up with rounabouts 37.5% damage taken. Or they could just work towards the current cap and not overwrite one another.
Modifying -% Damage Taken is a pretty big deal, so I'm not really sure what would make this sort of ability balanced.
Blink II, Stoneskin II - Able to be cast on others something something. Higher caps than the tier I spells something something. Not less potent than the tier I spells like Phalanx II was when it was first introduced something something.
Not very inventive, but giving someone 4 Blink images or 500+ HP of Stoneskin would be helpful. Well, not so much the four Blink images, but I won't rob SE of the pleasure of adding a useless spell here and again. Currently, one of the strongest Stoneskin effects in the game comes from Cure V or VI with a Orison Bliaud +2 equipped, and that just strikes me as weird.
As for enfeebles, just making the current set actually work on the majority of Notorious Monsters would go a long way. Even if the effect of a good dMND value was halved on said Notorious Monsters or something, that would be far better than just making lots of stuff flat-out immune.
Failing that, more enfeebles with subtle effects like Addle that actually work on even the most notorious of Notorious Monsters would be okay. Something like:
Old/Age/Cripple/Fatten/Clinical Depression due to Reading the Official Forums/I am Not Good at Naming Things - White Magic - Enfeebling: Lowers the target's STR, DEX, VIT, and AGI.
Muddle/Befuddle/Bamboozle/Mental Disorder and Disarray due to Posting on the Official Forums/I am Still Not Good at Naming Things - White Magic - Enfeebling: Lower's the target's INT, MND, and CHR.
Even if the effect of both of these could go up to -30 or even -50 for the monster for all aforementioned stats, they wouldn't drastically change a fight the way a high Slow value or Silence potentially could. The monster would just do less damage and take more damage.
Or just let good enfeebles work almost normally on Notorious Monsters, the same way everything else worthwhile does. I fear that's too much to ask for, though.
Also...
En-Not-Horrible: Provides an Accuracy and Attack bonus based on enhancing magic skill ON CAST and deals a percentage of damage dealt by melee hits as an additional effect. Maybe 50%. I don't know. My goal is to envision En-Not-Horrible, not En-Really-Good, so I can't say I've ruminated on it greatly.