Hi BastovBros,

if you want to make it easy and halfway realistic, accept your center of gravity, where ever it is, as long as it is on the centerline of the aircraft. Or bring it forward by a hidden mass on centerline. Then apply one upward but small force at the tail and bigger ones at each wing. So, you have three forces, the z components of which should be equal to the aircraft weight (mass*gravity constant), and the COG should be inside the triangle formed by the forces. Ftail*rTail = 2*Fwing*rWing! (r = distance from COG lengthwise)

Now you can steer up and down by altering the tail force and roll by reducing one of the wing forces and increase the other by the same amount.
When you add another sideways force at the tail always heading to the opposite direction than the sideways component of the current velocity vector, your airplane will even stabilize itself. In addition, you can use this to get a yaw steering.

And another tip, give the upward wing forces a small angle to the inside, that will serve as a roll stabilisation like upward swept wings.
So, all you need are four set forces to get precisely the balance I described. When you alter these with velocity sqared and some factor bringing the result to figures the physics system can handle, you get the real behavior of an aircraft - after some testing.

Have fun
Henning