I agree, I wouldn't dare fly this plane in a "park", especially if there are people around. If for some unknown reason this plane gets interference and goes down, you don't want to take the chance of hitting someone, or something.

Anyway, to answer your question like the others already have, yes, the plane will perform wonderfully on a grass strip. I simply point mine in the direction I want to take off, gun it to full throttle, and the Saito .72 will have it airborne in about 10 feet. If I were to hold full up elevator on takeoff, it would probably get airborne under ten feet, probably more like 7 or 8 feet.