On Aug 4, 8:55*am, Jim White wrote:
This thread is boring...what's the lowest heigght one should start an
aerobatic manoeuvre?

In the US FAR 91.119 Minimum safe altitudes: General
(b) Over congested areas ... [no lower than] an altitude of 1,000 feet
above the highest obstacle within a horizontal radius of 2,000 feet of
the aircraft.
(c) Over than other congested areas .... an altutude of 500 feet above
the surface, except over open water or sparsely populated areas. In
those cases, the aircraft may not be operated closer than 500 feet to
any person, vessel, vehicle, or structure.

Should one use the rudder when rolling in a clover
leaf loop below 500ft?

Yes, at the same time as the ailerons - your choice of any one of
those "boring" citations.

Go for it, Dude!