as for trying to enforce the issue Phil, it would be as simple as removing the Ad that doesnt have the correct information in it.
As for Photos are a 100% must im not too sure as there are those that have no clue of how to do this, but Location and Price should be a must!
EG.
[VIC] Item for Sale (in the title)
And again in the message with a more detailed location in said state... And a Price.
Just a thought as this is how some other forums work and seems to work well...
If the poster fails to have their ad in the correct manner a simple email to change and comply within XX hours or else deletion will occur
My 2c
Bryan