I'm glad I could help 
And thank you for a very good explanation of the parameters! I made PWM_CLOCK, PWM_PERIOD, PWM_DUTY_MIN and PWM_DUTY_MAX constants inside the library because they need no modification if you use the code as a servo library.
But in your case and any similar ones it might be better to make them parameters to the writeMicros() method so the caller can set them freely. Also a rename of the methods might be proper, because if you modify PWM_CLOCK it will no longer be microseconds you write. initPWM() and writePWM, perhaps?
Of course, PWM_DUTY_MIN and PWM_DUTY_MAX are only relevant for the servo implementation, you will most probably want to remove them completely or modify them to suit your needs.
/Sebastian