I have a world/universe that I wish to open up to other writers. However I am unsure how I should structure the licensing fees and rights of ownership over the world itself and what happens (basically things like in Forgotten Realms you can't just kill off Elminster)?
As Patches noted, play first, pay second.
I launched a shared story world commercial entertainment property, and I curate examples of others. It is possible to make money from a shared world, but the hurdle is getting folks to want to play in the world first.
You'll need to build a compelling world, lay out the rules clearly about how rights and revenue will be shared, and seed the world with quality content first. Money coming in your door is second (and may take many months before it actually does occur).
Take a look at the worlds listed at http://sharedstoryworlds.com and examine how they structured their legal agreements, revenue sharing, and copyright terms for some ideas about how your world could work. Look at how they have structured their world and the content inside it.
Also, take a look at Into the Far West. I know the creator behind that world, and he's pushing for something close to what you're describing (i.e., an entertainment IP people pay to play in). He hasn't fully rolled out that portion of it, but I want to point out how much he's already done to build and blow out the world.
Hope this helps, and good luck with your project!
I think you're thinking about it the wrong way. This isn't something you can make money off directly. What you can do is make a killer open source** world and an even better site that by game-izing it (like stackexchange did), draws in tons of writers to develop & use this open source universe.
**Note: do some kind of creative commons license that allows individuals to commercially use the universe, but corps have to pay
Rights of ownership -- wrong question again. the right question is:
How to manage Canon?