I get the idea that they're kinda a part of who they are but having a two handed weapon and having the book glued to my arm looks ridiculous.

 

I started a new game with a wizard and wanted to spice it up a bit with guns but I still have the book on my left hand even though guns are two handed, reloading the gun with a book glued to my hand looks terrible.

 

Is there a mod/option/something to disable wizards from always having their book on them or do I have to make a druid?

That's very interesting and may be a glitch. I also run with wizard and use a two handed sword as my primary and an Arbeques for my secondary. I no longer see my character carrying the book. Though, you will when equipping one handed weapons.

The thing is, if you use a gun, or a wand? its a two handed weapon but it only is used by one hand unless reloading(gun for example), you will have the book show.

 

But if you use a legit two handed weapon like a greatsword/arbeques it  doesn't show.

 

What I would love to see is to have the book not show as long as its a two handed weapon.

I see. Unfortunately I don't believe that is an option.