As someone who loves to create content freely with little or no guidelines, following the merit system could be difficult and impact the flow of my submissions. Nevertheless, it is a contest and one must accept the T&C to participate.
Having a system that enables you make a more rational decision is far better than one based solely on intuition. I think this good for the contest.
I really do not have much to add to the system you have created. It looks good enough for what you intend doing.
RE: Sensitive Information Inside