What you say about wing fuse interference is true - and those things account in part for the 10% variance in pressure I mentioned. That does not justify ignoring the low pressure that is experienced by the fuselage and the resulting lift.

It does not mean that the pressure values jump from a lifting low-pressure over the wing to some higher value right at the wing root and across the fuse. Pressure fields are omnidirectional and tend to equalize between different pressures. Think about it, if there were high pressure over the cockpit of your given plane and low pressure over the wing right next to it, the flow would tend to adjust and equalize with a local airflow component moving away from the fuselage- and you'd end up with very similar pressures over wing and fuse.

If I'm wrong, how do you explain the fact that calculations of performance using my method for wing area turn out to be so accurate on virtually everything flying?

Not only isn't a laminar boundary layer necessary, it isn't a factor on almost any model much bigger or faster than a 2m glider. On models, laminar flow is generally a bad thing, as laminar flow stalls sooner and creates more drag than turbulent flow at this scale.

Compressibility isn't even relevant, although planes designed for it, say the F-16, show how well the lift distribution continues over the fusalage.

It really is a discussion for the aero forum, so I'll quit this thread. If anyone wishes to discuss further, go post in the aero forum.