Did the airfoil choice on the P51D affect its maneuverability?
Yes it did because the stall behaviour of the Mustang, due to the airfoil, was very abrupt and it was much easier to get into an accelerated (high speed) stall pulling high G than it was with an airplane such as a P-38, which had wonderfully benign stall behaviour and could be manhandled all over the sky in relative safety.  At the beginning of a trip in the P-51 this was made worse by the aft fuel tank's effects on CofG which made the stick forces very light so you wanted to avoid radical maneuvering until you burned off the fuselage tank fuel.

The later versions of the P-38 with hydraulic ailerons and dive flaps were just about the best propeller driven aircraft in the sky in 1944, because at high speed they could roll as fast as SE fighters and had the benefits of crazy rate of climb and no engine torque effects, on top of the very gentle stall behaviour.   One reason the Mustang dominated, even though the Lightning's technical bugs were worked out by that time, was the P-51's performance and range was great AND it was only about 2/3rds the unit cost of a P-38.