I have split this topic off as it gas generated wider discussion.
Firstly it is already on the list of proposed improvments to have a separate page linked from the front page comments to enable members too see more than just the last couple of dozen - my view would be a minimum of 24 hours, but could be longer.
The length may depend on whether it is feasible, as also been suggested, to have a thumbnail of the photo in question beside the opening lines of the comment itself - this will help members choose which comments to open.
The suggestion to improve accessibility by including comments in a broader "search site" facility is also noted.
So far as the content of photo comments is concerned, I do not favour any additional Admin editorial function, beyond dealing with inappropriate posts under the Code of Conduct. Beyond that I do not think it appropriate for there to be any suggestion of censorship beyond that.