I'm not 100% sure what you're asking for but this may help. If it does I could really use that bounty :p
http://wordpress.org/plugins/wp-image-borders/You want images to not be in a box right? Like not have a border?
Also I googled and this is what someone else said about removing the borders:
"What you can do is in the Text Editor, first click on the picture. Then on the image icon that says Insert/Edit image. There you can change some things like border (fill in 0)."