Just scanning over the site, I'd think that'd you'd be able to configure a free image hosting site to work something like that...you might have to switch the pages around a bit so that the first page that you went to was a gallery view instead of an upload, but it would work I think...could just be because I just was working on my pic upload site though...

Regarding monetization, all the ways you listed would work...just a matter of what your audience would tolerate...

ND