My scrappy is about 8 oz. with a 2s 1200mAh LiPo and flies great. I had to put 1 quarter and 7 pennies in the battery bay in order to balance it according to the CoG on the plans.
The launch is tricky to explain, but take the wing in your main hand (Mine is right) and splay your fingers underneath with your thumb on the LE. Power up and use your fingertips to propell the wing forward, preferabley upwards a little bit. Here are some pics that I hope help you out a little bit. This wing is really twitchy, but quite stable if you don't go crazy with the sticks.
Ignore the dangling motor; the zip tie broke while I was reaquanting myself with how to throw it properly just now