Marvel Dice Masters: The Uncanny X-Men Dice Building Game Starter Set

What characters are included in this set?

If i have 2 of the marvel dice masters: x-men forever campaign box, can i mixed it with these and others starters? thanks

Will the Avengers vs Xmen boosters/gravity work with this starter? Or do I need to purchase the Avengers vs Xmen starter?

Is it worth getting this to add onto the main game? Worth getting if planning on buying the main game?