Controlling servo: how to determine the angle and needed pulse-width?
Your question was way too long to read.

These kind of hobby servo motors are controlled by the width of a pulse.  The standard range is from 1 to 2 ms, and should be repeated every 20-50 ms.  1.5 ms pulse width will put the servo in the middle of its range, with 1 ms to one end and 2 ms to the other.  Some servos can go a little farther in response to values a little past the 1-2 ms range.

Most will tell you the angle range they are intended to work over, so that gives you some idea of the angle change per pulse width increment on your end.

In the end, remember these are hobby servos, so don't expect a real datasheet with everything properly spelled out.  The best way to know what a particular hobby servo can do is to measure it.  Set up a jig that can vary the pulse width from 500 &micro;s to 2.5 ms and see what the unit does in response.