I fundamentally disagree that travel is an issue. With team private jets, with the operating budget, these teams have traveling down to a science. I don't think the traveling would be that much worse, it would be very minimal IMO...
However, I agree, it would have to be a balanced schedule. Play all teams 3 times (with the exception of 7 teams) makes 82 games.
Rivalries have been dead for a while, it's all media driven. Reality is public doesn't care about team a vs team b. There aren't many die hards of teams, generally speaking, people are a fan of players. The NBA world gets hyped because of match ups. In your theory, Knicks vs Lakers get hyped up... My theory give me Durant vs Lebron. There's no history between these teams yet this is what gets the buzz. This isn't the rivalry era between the Knicks and Heat, there's no coach hanging off players legs...
It might not seem like much but a balanced schedule over 82 teams would make travel much worse. In the playoffs what if the Knicks play the Clippers rd 1, they gotta fly back and forth cross country while say 2 Texas teams play?
NBA doesn't have rivalries like say college football but there are still matchups that people want to see. The pacers being able to finally vanquish the Heat in the east is a very real thing with interest to it. The Spurs/Lakers in the west a lot of those years. The Spurs/Mavs in the west....Rivalries in the rematch sense are good for business.
Top 16 teams make it sounds cool but I mean really who is the best team in the last 20 years to miss the playoffs? I don't even know off my head but I'm thinking it is a pretty forgettable team, not the biggest issue in the world.