RE: Take off or throw it?
I started taking off from the ground. I have never thrown my plane. I am not confident. It took a little while to figure out how the control surfaces should be when I do it, but now, its easy. And with my setup, the plane takes off vertically, which looks pretty cool. I don't think I would get the same effect from throwing the plane.
My guess to why they tell you to do that is because they think it will be more likely that you will scrape up your wing by losing control on the ground (which can be easy to do) rather than your plane doing a faceplant with a hand launch.