You should build a beta as soon as possible. However, the key is to keep your eyes open and make incremental improvments. Everything becomes clearer when real people start using your application.
One thing you could do that may help you make some revenue quicker is to publish your world in a form compatible with role playing games. You can do the publishing through a company like Lulu. Game rules are actually not copy-writeable, so making a resource for dungeon masters of the game dungeons and dragons is legal and the larger companies even have resources to help you out.
You will need some flavor text, but you could hire that through writers here or on eLance.
Email me through the site and I will get you some samples of others who have done it. Once you sell it through this medium, you will find that many people may want to create other content off of your world. If you wanted to do it on a decent scale, you coudl build a website, get your own ISBN and start a small publishing company. In teh gaming world you will not get rich, but it is a good stepping stone if your world is decent.
It does sound like a good invention. Keep going.