I am guessing that you actually mean when the AIRFOIL is aligned with the centerline?

You need to remember that the AoA changes with flight speed. The slower the model is flying the higher the AoA needs to be in order for the wing to make the lift it needs. At slow speeds near the stall the wing may be flying with a 5 to 7 degree angle of attack. At high speeds it may be as little as 0.5 to 1 degree AoA even for a symetrical airfoil. With a cambered airfoil like the 2412 high speeds may even see your AoA at 0 or a 1/2 degree negative. It all depends on the amount of lift your wing needs to generate to maintain steady flight.

During all these changes in flight speed and AoA your fuselage just follows along for the ride. In truth our models do not really need any incidence angles in the fuselage to wing. That angle comes from full sized aircraft where drag and speed are primary concerns and the wing is always set at the right incidence angle compared to the mininmum drag attitude of the fuselage to ensure the least fuselage drag at cruise speed range. But our models seldom fly at a steady state for more than a few seconds. Usually we are turning or looping or tossing it around so economy of drag is not an important factor..... unless you're a racer or fly sailplanes.

So for general sport flying models that spend a lot of time upside down make it all 0, 0, 0 (engine, wing, tail) angles with your 2412 and a close to neutral CG location . For trainers that spend all their time right side up building in some trim to compensate for the forward CG is worthwhile so something like -2, +2, -1 and a cambered wing section and it'll trim out with little if any elevator trim being needed. Such angles also ensures that the model flys with the fuselage at an angle that looks right to our eyes. Aerobatic models would look funny if the fuselage was level when upright and pointed nose high when upside down. Adding positive incidence to the wing compared to the fuselage would cause just this situation in an aerobatic model because the wing needs to fly with positive angle when upright but negative angle when inverted so the fuselage have to aim with the wing.