I think you can achieve nominator status quite quickly if they like a publication, even in early stages, but I've literally been sued before - for a pipe on a pavement issue - and it's horrible. I want to avoid it at all costs.
The last time I ran a publication that didn't insist on people using their own shots, there was loads of copyright infringement being submitted. I ended up completely paranoid about missing something and being sued, and closed it down. I also resented all the time it took having to check for copyright infringements. And explaining to people why they couldn't just lift people's photos off the web.