Is it possibly to check if timing has been retarded from the standard manufacturer timing in a straightforward way?

is using a timing lamp count as straighforward? if so, then use a timing lamp.

Depends if there are timing marks on the pulley. A lot of new engines dont have any marks (like the duratec) so you are relying on the sensor and pulley being in excetly the right place for the timing to be spot on. There isnt really a way of checking it then unless you make some of your own marks

David