Get used to it. FSS asking you to report a certain position is NOT controlling. FSS asking a pilot to report a certain position, or asking "can you extend downwind", or similar inquiries, has been accepted practice for DECADES. The purpose of asking the pilot questions is to enhance the airport advisory. I have never found their inquiries or requests intrusive. Keep in mind that NavCanada's FSS/Air Traffic Specialists do in fact CONTROL vehicle traffic on the aerodrome manoeuvring areas.. So perhaps they are asking if you can extend downwind so as to allow a vehicle or other aircraft to exit or cross an active runway.. for example: "Golf Echo Zulu Papa..can you hold short of runway 14?, traffic on short final". It is for our benefit.
Regarding the phraseology at the privately operated airfield at a mine/oil base camp;.. I suggest you talk to management about your concerns.
Also, as you can get Special VFR authorization at Grand Prairie through FSS, it is a control zone of sorts. It is not "uncontrolled airspace" per se.
Last edited by evansb; 26th Jul 2016 at 18:11.