Basic game info.
The stall horn comes on before CLmax.
The stall buffet starts when any part of a wing stalls. I assume that just prior to the buffet is CLmax.
Your best sustained turn is likely at 2.8 - 3g with the stall horn on just prior to buffet. Actual best turn will likely vary a bit but this is quick and close.
You black out at 6g. You can ride tunnel vision but as soon as you black out ease your pull.
High speed buffet precedes control loss. Reduce power and you can usually trim out if the stick isn't responding.
Storch prop is fixed pitch. There is a flight preference setting "WW1 Engine Governor" that prevents overspeed but limits power.
You must loop the Dr1 and Camel.