In my opinion if you are inspecting rural properties you should have some general knowledge of wells.
Most minimums required by mortgage companies in my area like to see 4 gpm over an hours time. Again in our Province one must be licenced to conduct such tests.
Construction or well type is also important. I have seen many wells in my practice which have been worked on improperly and resulted in the Ministry ordering abandonedment of existing well and requiring a new well. As in most things people moving to the country have no idea what is involved with wells and this is were an inspector can help as a generalist and point the clients in the right direction and give info that assist with country purchasers.