EDIT:: Just um.. click around it with the magic wand and right click on the selection and feather it 20 pixels. Then hit clear as many times as you want. Also, you can smudge it a little on the edges, or just make a new render layer and chalk spatter smudge it and erase where the edges are blended.
A little bit. Work on the text. Try a better border. Try this: Make a new layer then Select~select all~edit~stroke~4 pixel black (make sure it's *inside*). ~edit~stroke~3 pixel white (inside) ~edit~stroke 2 pixel black (inside). After that, change the layer type to 'overlay' or 'softlight', whichever looks better.