Have a few questions.

1. When Compulsory Evacuation Device is used on a Fusion card, does go back to hand or fusion deck?

2. When the effect of Raiza is used on a Fusion Card, does it go to top of the deck or back to the top of the Fusion deck?

3. If Grand Mole is flipped face-down with Book of Moon, then attacked does the player get to activate the effect of Grand Mole, and return to hand or does it get destroyed?

1: back to the fusion deck
2: back to the fusion deck
3: grand mole is destroyed and its effect is not activated

To explain further on sicjeff's answers...

Fusion Monsters can only exist in three places: the Fusion Deck, the Graveyard, and the Removed From Play area. If an effect tries to return them to the hand or deck, they are simply placed back into the Fusion Deck.

Grand Mole's effect activates before monsters are flipped face-up in battle. Since face-down monsters do not have effects, Grand Mole must wait until it's flipped face-up by battle, but at that point, it's too late to activate.