Hi there, Once a bid has been placed, GIN cannot be added nor days lowered or made longer. You also need your Seller wings before the GIN option is available. You can add more pictures, add more items to the auction with 'update.' Update can never supercede the original terms of the auction. No one can leave you feedback unless they traded with you. Here is a great link to familiarize yourself with Listia. http://www.listia.com/rules
It's a great and fun place. If things are done right, you will meet the greatest ppl ever. I guarantee that. Good luck!
I'm not really sure. Looking at it now I don't think you can. What I can do is change the bidding length to 3 days instead of 7 and change shipping to free.