Newbie Still Doesn't Understand Code

All right, I was playing around with NOP-ing pieces of the code with various degrees of success*, and I became curious about something.

Despite the fact that the "default" view is the normal pool of available spells, both the code and my tests seem to indicate that the Spell + Cost view when pressing Y mode is actually the primary mode (and thus any changes must be made there first), while the view the player sees by default is actually the secondary view. Is this actually the case, or am I making a distinction where there is none?

*My short-term goal was to allow spells to be available even if they aren't in the actor's spell list. I had limited success on that front. I NOPed C3/4FE0-C3/4FE3 andC3/4FE7-C3/4FEA and all the spells became usable when I pressed Y.  When I NOP-ed C3/4FD5, though, removing the branch granted access to the spells...but removed the ability to see the spells without the MP cost next to them.