Firstly, salaries should not be based upon precept but on the nature of the role for that particular council. So, a council with multiple responsibilities such as village halls, burial grounds, recreation facilities, etc. would undoubtedly set their salary scale at a different point from a council with no land, buildings, facilities etc., regardless of precept or even level of population. Similarly, hours necessary to do the job will differ.
As far as the second point is concerned, I agree that many clerks would apportion the time taken for tasks which are similar/the same in a fair manner but I also agree that some might not. However it would be difficult if not impossible to micro manage the clerk to the extent that you can identify exactly how long it took to do something like prepare a policy. How many, for example, "borrow" a template from another parish (given that lots of examples are on council websites) and then amend it to suit their own council? How do you judge how long it should take to do that? Surely there should be some trust in your staff?
Never forgotten the time I prepared a briefing document for my council on a particular subject (which took me a little while to research) and subsequently found a copy of it on another council's website who were contemplating a similar course of action! The clerk hadn't asked me or indeed acknowledged that it was my briefing note. She'd just removed my name!