Interesting view... Difference is that a stock photo is just one part of a bigger picture (as you said). However, a theme is everything that the users sees, not just a part.
I'm using Pastel and it seems perfect for the project.
No, I'm perfectly fine with Twitter Bootstrap and similar because its highly customizable and after a few hours coding, it won't even be recognizable.
I'm using an Admin template for a web app and its pretty unique.
I just don't want to be "mocked" because I didn't take the time and money to make a more unique interface. Like North Korea was mocked because the Democratic People’s Republic of Korea's site (http://korea-dpr.com) cost $15 because they bought a template of Themeforest.
I know it shouldn't be a really big problem, but I'm second guessing every decision I've made because I'm really nervous about this one. (I've switched between PHP and Python and Linode and Heroku about 15 times now).
Like johnpattiyson, I can't scroll the TOS.