Regarding holes 13, 16, and 18:
Hole 13 in the long placement is a par 4, but it is so wide open that good professional players probably made a mistake or missed their putt if they get a 4 on it.
Hole 16 is a very challenging par 3 for professional level players. Distance is not the key, placement is. The slope of the fairway, combined with the bottleneck as one approaches the putting area puts a premium on accuracey. While the second shot is blind, there is a light pole that is almost parallel to the basket. One can gage the distance of the second shot based upon the light pole. In some cases, a blind shot may be indicative of a par 4, but not on this hole. In high-level competition, good players will be familiar with where they should be throwing, where the "keys" are on the fairway (i.e. light pole), etc... I will concede that hole 16 could very well be considered a par 4 for amature-level competition, but in all honesty, par should be challenging to achieve, and just becasue an amature cannot achieve the par on a hole does not mean that the par should be changed for them. That is what separates amatures from professionals in any sport. Professionals are masters of their game.
Hole 18 is not a par 4. Two accurately placed shots and you can cash in from close to the pin. The second shot is not an easy one, but again, par should not be easy to achieve. And if amatures are getting 4's most often and professionals are getting 3's most often, that just reinforces why the professional players are in their division and the amatures are in theirs. That does not justify changing the par to 4 for the amatures.