I agree with bluskis. 500 from something or someone is easy to understand. Hieghts above ground preclude low level over the sea and unihabited ares, and as an early poster said, round mountains etc, non of which will add to safety, but remove the fun.
The no landing within 1000 metres of a 1000 person organised outdoor gathering has some interesting airfield closing potential.
Let's say renta crowd got 4,000 people together (not impossible 250,000 went on th liberty an dlivlihood march) organised an open air gathering within 1KM of Heathrow, Stanstead, Luton and Birmigham all day on easter saturday - that would shut down everything quite well under the new proposal. Even a good sized fete in the village near your local airfield would put you out of business on a summer saturday!
Keep it the same I say, and have sent my 2p worth to the CAA, an welcome their open consultation - well done to them.