the apparent wind, but not the true wind. Therefore, it seems possible that the component of the lift vector parallel to the true wind could be greater than the magnitude of the force vector lost from not being downwind. The attached image illustrates this possibility with Wₓ(Some Angle) < Wₓ(Downwind), but Wₓ(Some Angle) + Liftₓ > Wₓ(Downwind).

https://en.wikipedia.org/wiki/Forces_on_sails
https://en.wikipedia.org/wiki/Apparent_wind#Implications_on_sailing_speeds

As for 2+2 = 4, so does 1 + 3 = 4. It appears to me, but I'm not an expert, that lift converts kinetic energy of the air into kinetic energy of the airfoil.

Here's some examples I'm basing that on; it seems to be talked about the most with turbines.
- https://physics.stackexchange.com/questions/143155/do-wind-turbines-convert-the-kinetic-energy-of-air "Therefore, the wind turbines convert the kinetic energy of the wind into electricity, and the kinetic energy of the air downwind of the rotor is less than the kinetic energy upwind of the rotor."
- https://www.simscale.com/blog/2019/09/wind-turbine-blade-design/ "deceleration of air"
- Looking at the flow of air over a wing, it's slower behind and near the wing.
- https://www.mpoweruk.com/flight_theory.htm "The turbine blades thus experience lift and drag forces, similar to the aircraft wing, which set the blades in motion transferring the wind energy into the kinetic energy of the blades"