Duncan
Perhaps you are right, but I always thought "expert" players was the target for par. Of course, back in the day an expert player was about scratch! To me, if one is a pro he is an expert...its just that some experts are better than others.
+7 to +10 seems very high to me for touring pros. Think of the best scoring average on any given year for the touring pros....69ish is usually the Vardon Trophy winner...so I make it +6ish for the best touring pros. Regardless, par should be sub 70 for nearly all courses pros play and handicap players should not think in terms of par because that was not a concept developed for them. Bifurcation started long ago, its just that golfers failed to recognize it.
Ciao