I saw you attach the lxf file using forum's function, but remember in this way you used about 3/4 of you storage space available, so you will be not able to do it again, because the lack of available space.
About images hosted by imageshack, there isn't any problem with the forum: I used imageshack many time.
How did you include the images? You simply have to encase the direct link of the image with the "img" tags.
[ img ] image_direct_link [ /img ] (without spaces)
However, you could use different decals among those available.
As we know LDD has not all parts and decorations, we could consider "how LEGO would have done this set if only these parts would been available?".
It's a choice of your own, however.
PS: note that the image should be a preview that allow other user to easily identify the set.
As the Barracuda is a big set, you should use a bigger image (in this case, the maximum size allowed of 512 pixel is adequate).
This time I modified the post for you. ;)