I vote for the artwork being inside front cover, assuming the font will be a colorful one. Often times I've been grabbed by black-and-white intricate illustrations opening the hardcover as if they are inviting, "welcome, this is what you're getting into."

I like the shading of her hair and the flowers. All of them are a little different in shape, must have taken you a long time. Drawing one flower/leaf at a time explains the variations a bit.

I Thought It Would Be Zombies looks neat! I'd love to read the final comic book. Btw, the art style reminds me of a graphic novel series I've read somewhat, didn't finish, and now regret not finishing - Saga.

About that shape language, you can write art-theory and stuff like that on hive, you know. You clearly have the knowledge and it might help a lot of aspiring new artists.