You said that you have to be 80-85 to get heirlooms. On my first char ever (undead rogue) i played a lot of random battlegrounds and i got the pvp shoulders. It takes time but it was totally worth it :D. And btw great guide.
You can smooth the hard edges of a selection by feathering. Feathering blurs edges by building a transition between the selection and surrounding pixels. This blurring can cause some loss of detail at the edge of the selection.
Easiest and most flexible way in my opinion is to do it with a stroke on the layer. Double click the layer in Photoshop, click on stroke, ensure preview is checked, then do a white 3px stroke.