Microchip Advanced Part Selector - Difference between CCP, PWM Outputs, PWM Channels
Yes the two coulombs are a range. The right coulomb is the maximum and the left coulomb is minimum. 

PICs have lots of ways to generate PWMs. What you are seeing is all the different kinds of modules that PICs contain. The module depends on the family of PIC and the model of PIC in the family. 

PWM channels refer to how many independent time bases you can have. This covers both independent PWM periods and duty cycles. 

Max PWM outputs refers to how many pins a PWM can come out of. Some processors can multiplex a single PWM to many pins.