Verdun:
On starting the game the R5 rudder is set slightly left. However, if I adjust the rudder trim then reset it, the rudder does return to centre. I was wondering why you didn't adjust the trim in flight rather than stand on the rudder pedal*, but maybe you didn't realise the R5 had adjustable trim?
I also tried the A-8 Mk108 wing cannons, but the muzzle flash is working for me.
*edit- or twist the stick, same thing