I think you nailed them all.
Tradition is probably most prominent in the NHL. The handshake at the end of each playoff series speaks volumes about whats good about sports. In a gladiator type sport like hockey played at the highest level, they still shake hands like five year old kids after a tee ball game.
Along the lines of the Stanley Cup, it's great that they don't celebrate conference trophies because it's not they one they strive for. The captain poses for the picture, and that's it. I wanna say Crosby is the only guy who raised the trophy or skated with it and he caught some flack for it. Guys also don't even touch the cup until they have won it. The NFL and NBA are notorious for taking pictures of players with the trophies leading up to the championship. Not in the NHL.
I love how each player gets to spend a day with the cup. Those commercials ESPN used to run when they had hockey were great. One where someone gave their baby a bath in the cup. Another made a jello mold with it. One guy took it fishing with him. I think Brett Hull locked his keys in the car with the cup in the back seat (I would think that one was scripted).
So as far as tradition the NHL is king to me. Even with the Winter Classics, playing in the throwbacks, out in the elements. Other sports should try to capitalize on that idea. NBA could play a game out at Rucker Park in Harlem. MLB play a game on the Field of Dreams field, or Doubleday field in Cooperstown. I think they always played an exhibition game there unitl some years back.
First off, I sure as hell didn't nail them all. I might've gotten many of the prominent ones down, but you got some of the ones I didn't mention.
Out of the four major North American sports, I would agree with you that hockey is probably the steepest in tradition. We can do best trophy in sports for another discussion, but I think that's the Stanley Cup, from a team standpoint, it's not even close; the other one that comes to mind is the Heisman. Also unlike many of the other sports, the players get to celebrate first, it doesn't go to the suits (owners, GMs, or even coaches).
In addition to not touching the conference trophies, I like how they don't touch the President's Trophy for regular season winner.
Funny you say that with Field of Dreams, my brother who isn't much of a baseball game has made that suggestion. I think it be very tough to have a regulation baseball game at a temporary structure. The closest you've had is when the Rays played games at the Braves ST facility in Disney World and before that the A's played them in Vegas, while Mount Davis was being constructed. The novelty factor would be great. They used to play an exhibition game at Doubleday, the fake site of where baseball was founded. In terms of the NBA playing in Harlem, that would be tough given it's a winter sport. They could play now, but do you really want a late season game being decided this way? The WNBA has played games at Arthur Ashe Stadium and they've played preseason games at Indian Wells.