Using just the basic/default JW FLV Player skin..
How can I position the logo on the botton right, about 20 pixels up?
Is there a default 0x,0y datum?
Do PNG files keep their transparency?
I didn't find the basic var description below exact enough to answer these questions.
logo (undefined): location of an external jpg, png or gif image to show in a corner of the display. With the default skin, this is top-right, but every skin can freely place the logo.

PNG files do keep transparency.
You can move the logo any where you want by editing the player source file.