A pedal pot should have a long working life , but will of course cost more because of this. Pots tend to oxidize after a few years, causing noises when turned. A dirty or oxidized pot can be temporarily cured by spraying it with contact spray and turning it back and forth a few times. You d get the strongest level without any volume pot at all. Active EMG pickups use only 25 kOhm, I believe.
Impedance is frequency-dependent, meaning that the resistance varies with the signal s frequency.
That s what happens when you turn down the level pot on a guitar and the treble decrease at the same time. For example, if you turn down a high-impedance pot just a little, the volume will drop drastically. Other models may use different values, but my guess is that for volume pedals, roughly the same values that your guitar pots use will do. The taper is the pot s response curve. If you feel that the response of your expression pedal is too abrupt, and you cannot adjust it with the G-Force s calibrating curves, you could try changing the pot in the expression pedal into a similar but logarithmic one instead.