Returning to Alternate Universes

When I first started writing I wanted to write massive epics like the Lord of Rings series and Star Wars -- the kind of writing Ian's working on right now. I was around six years old when I started and soon realized how difficult it is which is when I switched to playwriting at around eight years old under the false assumption that it was easier than prose.
When I began playwriting I accepted the limits plays could generate for an audience and have never deviated from setting my plays in the present day reality. However I abandoned the importance of setting and plot and focused entirely on the characters.

I am now returning to prose for the first time and taking big leap by trying fantastical settings again. I've created an alternate universe complete with a timeline a few years ahead of our own. I currently keep a detailed wiki with the all the information I have on the alternate universe and its inhabitants but I have no intention of revealing it until I get a few stories out there already. Until that time, have fun figuring things out on your own.

Right now I'm more concerned with how others have fared with using large stories set in alternate universes. My questions are:

• What time period?
• Approximately how many characters?
• Was it set on a different planet, i.e. different geography, etc.?
• How much time passes in your story?
• How far or to how many different locations does the story take place in?