seanreit,

You're first assumption is incorrect. Rotary output servos are rated in torque, which is a combination of force over distance. It's inch/ounces. If a servo is rated at 110 in/oz, that means at a distance of one inch from the center of the output shaft the servo can exert a 110 ounce force. If you hook up closer to center the servo can exert a higher force. Move out, and it's a smaller force.

There are programs available to calculate what is called the hinge moment, or the conrol power needed on a specific shape and size surface at a specific speed.