You can store the substitute images at Auctiva (on your account in Images tab) or anywhere else on the web, like Photobucket.
You can use Dreamweaver to update the stock template (I do the same with my code builder) and then copy - paste the code into the custom template editor. You get to that from the LISTINGS tab and lower right on the page to Create your own Template. You can also find the current template code at the Customize an Auctiva Template link.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .