1) Preparation plays a big role in classical chess, but in blitz and rapid it doesn’t play much of a role at all.
This was new to me. On the surface it makes some sense, but I'm not sure what the underlying reasons are. If it's true, does this mean that the traditional start position (SP518) is best played in fast games, and chess960 is for slow games?
2) Any player in the world -- even the best -- will immediately start making mistakes from the start.
I've discussed this before, in A Highbrow Dismissal of Chess960 (December 2010):-
The start of a game is two players following a known path for 'X' number of moves, after which they follow computer based preparation for 'Y' number of moves, after which they are on their own. At this point there are three possible outcomes: either they agree to a draw, or one of them blunders, or they continue playing as best they can.
In SP518, X+Y can take in 20 or 25 moves. In the other 959 chess960 positions, X+Y is a move or two. The sporting side of chess involves a player confronting the unknown, not repeating memorized moves. Is chess a sport or a rehearsed exhibition?
3) People will have a harder time following it because the position gets so chaotic early on.
People also have a hard time following a game starting with SP518, because they don't know when the players are following a known path and when they are on their own. It's easier to sacrifice a piece if you've analyzed it using an engine. Comparisons with professional wrestling -- which is not what it seems to be -- are appropriate.
4) Commentators have a hard time explaining what’s happening.
This is only true of the opening. Commentators can't use the same approach they use for SP518, because it requires experience with chess960. How many commentators have this experience?
In his recent match with GM Vachier-Lagrave, GM Caruana won the chess960 games +1-0=2, but lost the overall match. How would he have done if the match had been exclusively chess960?