Hey Swoozie,
We are just trying to get this thing started so any input is very welcome. Below is what I was thinking for your question.
So we can critique the shot if asked to but should we critique it in the day/week topic?
Sure, (we can play this one by ear, if the tread gets too big maybe next time we could make a critique thread) but only critique it if the photographer says so. (some will post but don't want to hear anything bad etc..) now I do think it's ok to say "Hey ___ nice shot" or something like that. (something Nice to say) The big reason is we have every skill level of photographer on here, Example: A New photographer mite send in an image they are happy with because they didn't cut off someones head. And that may be huge for them (they may even say so) And I think that is great, because we all start somewhere and the more you shoot the better you get. If someone critiques the image they should keep skill level in mind. unless they ask for harder critique etc... (poster should tell us what skill level they are for that type of photography) For an example you may be pro with nature type shot but not so much with portraits etc...
I like that you said the first photographer that posted can start the next weeks day/week topic. Should this be set in stone? Or are you saying the option to start goes to the first photographer that posts and if that one doesn't any volunteers can?
Every week we need to start a new thread, I think anyone can start it, but I would like to see a person that will post a image start the thread mostly. This will make it so if you want to start it you need to post something. You know it's all about taking more shots. If you want to set it in stone just say so. I think the first few weeks will be getting every thing set just the right way.
And are you saying that the original rules should stay but other rules/challenges may be added by the topic creator?
No, I think as time gos rules may change (this thread should be use to take a vote or something like that to change or add rules.)(I just put in everything I could think of at the time, and I'm sure there should be better ones) If you think something needs to be changed or added just say something here. Right now we are just trying to get the rules set. Even though (the title should stay as "picture of the day/week and the dates"

Example:
Picture of the Day/Week 01/28 - 02/3 because some may past post (this opens it up for film photographers or computer/internet problems or even if you couldn't post one that week but you shot one for that day/week etc... good for vacations)
Challenges may be done by anyone.
Example: Right now I posted a image of a candle. The
Title doesn't have any topic and shouldn't have just the dates etc. Now you post a image, lets say it's an image of a red ball and you put in "I challenge you to make an image with something red or with a ball etc.." Now the next photographers comes around they can post any image (like I did) or they can take you up on your challenge or even challenge other photographers with something different. The next photographer come around they can post any image or take any challenges etc..
For an example Maybe I would post an image with something red the next day or I may pick a different challenge all together. Not every challenge will be met or maybe they all will. It is just an idea to get people trying something different. Maybe the next day we will get 100 images posted with something red in it, who knows.
dose that make sense?
The point is to keep shooting, posting, being creative and to have fun.