Almost half my traffic comes from referring sites. I only post to Facebook and Twitter.
I suppose that someone else could have a link posted too... but I don't know.
As for the photos on the top of your facebook page - You can click on the photo and a little "x" will appear. If you click the "x" the photo will be removed. Of course you'd have to do that for each photo... I don't know of a shortcut.
Where do you post that you have more luck with than Facebook?