There was a comment made about age and GLOC potential. In all of the aviation medicine research into g tolerance there is no indication that increasing age results in an increase in susceptibility to either loss of vision or loss of consciousness.
After some incorrect comments on the use of flap in the Hunter I think that most of them have been corrected. However, to summarise:
There are no g or rolling restrictions with flap selected. When any flap is lowered a nose down pitching moment occurs. The speed limit using up to 4 notches/38 deg of flap is 300 KIAS/0.9M. If 300 KIAS is exceeded the flaps start to blow up and no structural damage occurs. If 0.9M is exceeded (a high level problem only) the aerodynamic loads on the elevator exceeds the output force of the elevator hydrobooster and 'jack stalling' occurs such that the elevator cannot be deflected trailing edge up and so the aircraft continues to pitch nose down; the recovery is to select flaps up, idle and airbrake out. NB that the elevator (and ailerons) and not fully hydraulically powered but are manual controls with powerful hydraulic boosting.
Pitch control is via the elevator and pitch trimming is by deflection of an electrically driven all moving tailplane. When flap is lowered and the aircraft pitches nose it is countered by an aft stick/elevator input. This is often done whilst manoeuvring and therefore no trim input is made. Even in this case, so long as the IMN is less than 0.9 you will always reach the stall before full back stick and so this trim change never limits pitch control authority at low altitude.
As has been said, lowering flap increases drag which is why, in general, 2 notches are used when manoeuvring with flap. 3 or 4 notches give you an increase in lift/instantaneous turn performance but the advantage is outweighed by the increase in drag.
It is quite usual to use flap for some looping manoeuvres in Hunter displays and there are, quite justifiably, different techniques used by different pilots.