Lately I've been asked to get involved with several idea stage start-ups. I've read feature specs and looked at scetches. I've read executive summaries and been asked to sign more NDA's.
You know what drives me crazy? All these ideas. All this time spent thinking about doing something and then, in the end, very little doing. I understand why it's hard to get moving, but I have to say STOP! Enough. Stop the planning, thinking, and writing. You should be building the product!
Some of your assumptions are wrong. You will change direction a few times when you get user feedback. It won't work the way you plan it to work. Users just won't do most of the things you think they will do. The "brand" won't work. People don't care about your name or your slick design.
None of it matters. The only thing that matters is getting a product up NOW. Build something. Don't be foolish and build something that doesn't solve a real problem (many do that), but do build something NOW. Get someone to use it. Test is. Ask them what they think of it. And then, re-do it. Again. Until you get some data that says "this works!"
I know it's hard. It's supposed to be hard. That's the point. Otherwise it's not worth doing. So, get on with it. Start building something.
Enough writing for me. I have stuff to build.