I decided to test some of these ideas out, first by not disabling the spellbook in the first place so I could see what happens.
I changed the Spellbook's orderid to Roar. Inside of the spellbook is Warstomp. I created a trigger that ordered my hero to cast Roar (So that it might open up the Spellbook), and then cast Warstomp. However, when the appropriate action occurs that should order my Hero to open the spellbook, the spellbook icon "lights up" as if a player had activated/clicked on the icon, but then doesn't open, and Warstomp is never cast.
If it helps, I'm trying to create a "Blink-Stomp" ability, one that will have the hero emit a Warstomp effect once they teleport to whatever location the player clicks via blink. I.e., the trigger looks like this:
Event
Unit finishes casting an ability
Condition
Ability being cast is equal to Blink
Actions
Order Unit to cast Night Elf Druid of the Claw - Roar
Order Unit to cast Orc Tauren Chieftan - Warstomp
EDIT: I also attempted to use a "dummy caster" to perform the same effect, by creating the dummy caster at the hero's location whenever the hero finishes casting Blink, but that does not seem to work either. I believe I created the caster and trigger correctly, because whenever the hero finishes Blink, the ground warps slightly, as it would if Warstomp were cast, but there is no other Warstomp animation, no damage is caused, and no stun is given to enemies.
EDIT 2: I solved the problem. Turns out the targets weren't taking damage or being stunned because they were elementals. /headdesk. I went with the Dummy Caster solution, and now it works fine. Thank you for suggestions, however!