I'm going to go with yes and no. Like most Form weaponry, the sketchbook is something that comes with the Form. So different Spheremorphs will have different sketchpads. BUT, if a Spheremorph has both a Scribbler and a Cartoonist Formsphere, they would use the same sketchbook. However, while in the Cartoonist Form they can't use the Scribbler's reality-altering abilities, and while in Scribbler they can't summon Cartoonist creatures.
Iriscriptor-it's a pretty name, but i'm not sure the writing component fits with the abilities. And now you sparked another Form. Heh, this could be interesting...
Another idea i had was something like Gold Chemist, but for others. I think it could be an evolution of both Chemist and White Mage so it would look something like this:
White Mage -> Form X
Chemist (Gold) -> Form X
I think this is a bit of a gimp to the White Mage portion unless it also works for the Spheremorph as well. so you could store anyone's health in gold, and use it as needed on whomever. contact would be a must....
Really the only reason I put this on here before it's fully fleshed out is so Silus can tell me whether or not it's legit.