Whatever numbers anyone has for lift curve slope, aero derivatives etc they must to related to both Mach number and Reynolds number because the flying qualities and aerodynamic characteristics varied markedly with Mach and airspeed.
The ADD limit was 20 units in all configurations, and at low speed (less than about 300 KIAS when on internal fuel) with flap and droop 0-0-0 this was reached well before any buffet. At ADDs approaching the stall a pitch up developed and there was insufficient tailplane authority to counter it such that a loss of control was inevitable. Therefore, simple considerations of CL max are not really valid as the high AOA characteristics were very complex. Between about 300 KIAS and corner speed (about 450 KIAS with no stores and internal fuel) there was a good buffet margin which occurred at less than 20 ADD. In the blown approach configurations (30-20-20 and 45-25-25) there was again no buffet at 20 ADD which, as well as being the limit, was the value used on the approach. The only time when a slightly higher ADD was sometimes used was on an unblown 45-10-10 approach when you could go to about 20.5 units. Note that the aircraft had an audio ADD system that was the prime data source to the pilot; the gauge was not really used.
There were some interesting characteristics at high IAS and high Mach. Tailplane power reduced quite markedly at high Mach numbers (which is probably why complete loops were not cleared). Directional stability also reduced at high IAS and I believe that intake momentum drag was one contributory factor. This meant that above about 550 KIAS the aircraft would not fly slipball central but needed a small sideslip angle to achieve directional stability. Also, at high IAS the roll performance reduced dramatically, I believe due to wing twisting moments from the ailerons, although high Lv and adverse yaw could also have been a factor.
One other consideration is that full forward stick to full aft stick did not give the complete range of tailplane movement; the trim tailplane angle determined the range of movement.
You have chosen to try to model an aircraft with some of the most complex flying qualities that I have known, especially at low speed or very high speed. But from about 350 - 550 KIAS at low level it was incomparably good!