Modern defence (going to get shot down in flames!)

I was following a book about my recommended white opening, and the author made mention of the 'modern opening' on a whim I got a book about it, by Jon Speelman.

It seems to be an opening complex that can be used against both e4 and d4; I would be interested to hear people's opinions - is a 'hyper' modern defence like this a good learning exercise?

My white repertoire book talks a lot about the Colle-Zuckertort, so would having a black rep with a fianchetto be a good thing? (i.e have similar theory in both white and black openings?)

Yes, you can play Modern/Kings Indian/Pirc/Reti Setups against everything.

You can also learn alot cause you're basically give white all the space and then attack his big center, so you try to prove that his space advantage is not only an advantage, but also an attacking target. Thats the main point of modern systems.