General method for phase-locked loop filter analysis and design

[promach]

For this General method for phase-locked loop filter analysis and design paper , I have few questions:

1) In section 3 Classification for PLLs , could anyone help to explain on this ? and how to derive this frequency roll-off expression ?

The difference between order and type gives a measure of the ability to filter out high-frequency phase noise contribution, in such a way that the high-frequency roll-off is given by the expression: -6.02  (order – type + 1) dB/octave.

2) Could anyone prove mathematically that "The order needs to be higher than type only when extra attenuation of phase noise is needed" ?

3) Besides, could anyone derive expression (7) ? and how does this inequality expression guarantee that the transient and filtering capabilities of the PLL is unchanged while increasing the hold range (which is proportional to K_pv, according to author ? ) ?