Vae has 1 Attack and 1 Defense; her Light Arrows can't even hit through anything's Defense except the boss, so unless Brill's throwing Fire or Water around, it's not a very useful spell for her. She's a rookie spellcaster that isn't even really focusing on combat magic, so she's very weak offensively, especially compared to Aida's Crossbow or Garett's magic. Her support magic is where she really shines, and if Brill goes down, she'll have better luck using Rejuvenate than trying to finish off an enemy.
Looks like the Through tag got enabled on those two books. Somehow. Well, that'll be fixed next patch.
Wizards probably knew more than the basics way back when the Subterrane wasn't, well, the Subterrane. But they are school textbooks; some of them would naturally be about the basics. (Case in point, the first one, which just asks what 8x8 is.)
Holy Water does need to be preceded by a flash of light to hit the Shadow. That said, a Shadow is Undead, so it's going to hit really hard against it. It's also got the first direct OHKO move you've seen, and the second if you include Shell Slimes' counterattack. OHKO attacks are all conditional, and usually pretty telegraphed.
I think I'll upload a bugfix patch tomorrow, along with something for Screenshot Saturday. I've gotten some more work done on base mapping, but there's still quite a bit to do.
