I don't work for a taxi company, I am a self employed owner driver.
even as a private hire taxi driver, you are by your own words "employed owner driver" being a professional driver myself the phrase that is often used is "for hire or reward"
a pimp would be someone in my mind, that coerces a woman to part with money having performed a sexual service. where as an agency wouldn't use intimidation or threatening behaviour to receive their "cut"
so if i am employed by an escort agency to drive a WG to her client, then i am not a pimp. if the WG gives me payment it is for the service of driving her to her destination that i am being paid for. this same principal is used by the agency themselves, they are simply there organise a booking for the WG... this is why you get the disclaimer about "we dont sell sex, what happens between the client and the girl is at thier own discretion" etc etc etc... you get the picture.
incidentally, out of curiousity i wonder if there is actually a "pimp/madam" forum on the internet as there is this site for punters and others for WG's