All of these are basic and necessary questions that need an answer before you even start typing it up on the topic submission form. You can't just say "This should be a world." and expect anyone to think that it's a good idea. Most good ideas on this forum are more than one line long.
Hmm, i think Dragonspyre fits into that subject. If you've been in it, it is full of lava, and has a huge volcano in the center. Maybe am earthquake world?