The example pictures at the end blew my mind. Also his energy was kind of motivating. 

I was wondering if there are any criterias that have to be met, in order to earn money by referring photographers.
Could I open an account and earn money with referrals only, without ever uploading a picture myself?

I think the biggest problem is poor composition. That's why pictures two and three look indeed like snapshots. In both pictures the upper third is not used. That looks strange, since you took a pictures of something that's usually high up. So you would expect it to be more on top of the frame and not on the bottom. This might be a different story, if you had a nice blue sky and isolated the lanterns against it.
The first picture needs a perfect angel to look right, since even small differences in the lines make it look wrong.