[Reikou]

Grandovyn retains its Book Smack Special Skill while in sword form ( Which is quite beneficial, by the way ), and basic attacks made with the transformed weapon, despite their 1 Range, seem to count as ranged attacks since they trigger things Like Forgery's Resonate Passive.

[Snake]

It's because Grandovyn (and any Shifting Tome) behaves like a Mutated Weapon, the type changes but not what the weapon is. So you can use Book Smack with it, or get 'sounded' by a Forgery.

That skill is only made to enable the Tome to use Sword skills in exchange of casting magic, and vice versa.

[Neus]

All weapons treated as other weapon types probably behave this way.

[Lolzytripd]

Dev is 100% correct, I also feel its better this way, breathes some variety in.