I submitted something for the old Photo of the Week competition. However, it probably won't get viewed.
Can I post a question on the main site asking for a rating of my photo?
We don't do "ratings" here. But if you'd like to receive feedback and critique about a photo, we do that.
It all comes down to how well the question was asked. "Hey guys, what do you think of this photo?" is a very poor question, and won't get favorable responses. However, if you tell us specific areas that you'd like to improve (composition, "mood", lighting, staging and placement, a particular effect, etc.), or maybe what you were trying to achieve, that would be a great question. I'd certainly like to see that question on the main site.
Also, great questions have good titles. If 100 people post questions with the title, "Please review my photo", how are we able to distinguish them if we're searching for them? I appreciate it's difficult to come up with a single sentence title for what is possibly an open-ended question, but perhaps something like, "How can I improve this shot of water from a garden hose?" It's specific to the subject.
Thanks for asking here on Meta. I hope you do ask for critique of your photo over on main. =)