you're looking at a long and difficult road with a game like that. I'd suggest, if you are willing to commit, recruiting a concept artist straight away. He'll be able to bring visual to the ideas and concepts you're creating in your rough draft. This not only stimulates your own imagination, but it provides a glimpse into the game for people who are interested.
Once you've gotten the core concepts down, and are starting to flesh out your ideas, I'd suggest either start looking for a second designer to have them help you out (they'll pick up things you've missed and offer new ideas that didn't occur to you) or make another post about it on this forum (I'd suggest the former).
Then you'd want to look at getting programmers and a level designer on your team, the programmers will start creating the mechanics of the concepts you've already finished, and the level designer will start making the basic layouts of the maps.
After that, I'd look at getting your graphics designers and music creators, they're unnecessary until late in the development stage, as both require a full concept to work well.
Other advice I'd say is to create a blog instead of a tumblr account, and give updates and information on what you're doing. We don't need your entire drafts and concepts, in fact I'd recommend you stop right now. Many people would be self-inclined to take your work and create their own crappy version of the game and claim copyright. As long as you don't give out specific details, posting about things you're going to implement among other stuff would help you create a small community around the game, which helps a LOT (more then people realise).