Ask HN: Open-source a startup?

I've been building my startup for the better part of this year, but have come to a point where I no longer can afford to pay designers or programmers. However, I'm entirely focused on getting the site built, as I feel it is the perfect time for such a product and it will greatly benefit our world, especially in these tough economic times.

I've been considering ways I could finish it while not currently having the funds. One is getting a loan, but I'm quite adverse to the thought of putting myself in such debt, especially with other responsibilities like having a roof over my head coming in first priority.

Another is crowdsourcing, but the problem with that is that I'm worried if enough people hear about my idea, someone with bigger pockets and more connections than me may steal my idea and launch it before me. The third option I've though of is turning my startup into an open-source project, with only qualified people being allowed to work on it.

Has anybody ever thought of this? What are some pros and cons that I may not have thought of? Also, how would I make it open-source without giving up full control of the direction it goes in?