Yes, you get both bonuses.
So Expert fencer with Rapier and Main Gauche who does a double parry is attacked with one handed melee weapons at 6/(DX-2) and subtracts five hits from each attack. I.e. any attacker with DX before these adjustments of 16 or less has a 6.08% chance to hit.
My suggestion is to apply the occult zap which is a special spell and not a melee attack.
My suggestion is that double and triple damage results against a six dice defense ought to be very rare, but the exact result is unknown.
https://www.hcobb.com/tft/TFT_Saving...rcentages.html