I know what your asking on both. w00t!
Ok, for scale, you select the brush, then hit "s" to bring up the surface property window, and along the top, to the right side, will be x scale and y scale. they will be at values of 1. Change those to whatever you want and that will be the factor of scaling, Hit the button apply face or apply brush on the window depending on what you want.
For the sky, it needs to be pbsky1 and not sky1.
hope this helps,
Cusoman