I want to change from the flat premium to the standard plan...I currently have several hundred photos stored on Auctionwatch...so my question is Do I need to delete the photos before changing plans? Will I be charged for the storage, or will they be deleted automatically with the switch?
You won't have to delete anything when switching plans. To change plans, go to your My Account tab and click on My Payment Plans. You don't get charged for storage under the Standard Plan -- the only image host fees you would get would be if you launched somewhere other than AW, and you used the images hosted here in that auction. As long as you are launching from here, you are okay.