Paul,
I have no problem with newer members asking about topics that have been covered before. Sometimes, the search function is lacking, so repeat questions are understandable. Also, sometimes it's good to hear new perspectives (or even see how your own perspective may have changed over the years).
I had an almost identical situation to yours, where one of my favorite risk/reward par 5s was changed overnight to be one of the most ferocious par 4s I've ever seen. And I used to rail about it for years. I even thought I was more justified because the hazards in the drive zone, small green and OB left were clearly geared towards it being a Par 5.
But mainly through this website, I've been turned around on the subject. I've come to accept that the par is irrelevant on that hole, and that I should play it the same way, regardless of what the scorecard says.
Like you indicated in your first post, it should have no effect on medal or match play. Taking it even further, it probably should have no effect on handicap, either, as the USGA should give the hole the same score for the course rating. It's really just about the ego of wanting a short pitch to set up birdie instead of trying to save par.
It took a while for me to accept that premise, and it's still tough, because I think we all generally prefer the 1/2 par hole on the "easy side." But, I just changed my attitude on that hole from "expecting" an easy par on a reachable-5 to relishing the challenge of toughing out a very meaningful par 4.
I did a quick search using "does par matter" and found a few posts here. I know there are many more, and I may have some luck finding them with some other search phrases.
http://www.golfclubatlas.com/forum/index.php/topic,17410.0.htmlhttp://www.golfclubatlas.com/forum/index.php/topic,13820.0.html