I personally have no idea what is proper for a Blackjack tournament, but I've played in a quite a few live Poker tournaments.

It is never okay for someone to give advice or other information to another player during a hand.

Also it is very bad etiquette for others (players and spectators) to blurt out information (i.e., “damn I had a Jack”), discuss their opinions about player in the hand (i.e., “That guy hasn’t played a hand since October”), or the hand itself (i.e., “Possible flush on the board.”) while the hand is in progress.

I heard never heard a rule or matter of bad etiquette for players to discuss anything while in-between hands. This includes talking to other players or talking to spectators. That happens all the time.

There is a set of rules offered by the “Tournament Directors Association” (TDA) which many big tournaments adhere to. Not sure where the current list of rules are posted but I found an article about the 2007 rules. #12 says:

http://www.pokernews.com/news/2007/02/tournament-directors-association-new-poker-rules.htm

12 No Disclosure - No Advice - One Player to a Hand- Players are obligated to protect the other players in the tournament at all times. Therefore, players, whether in the hand or not, may not:

1. Disclose contents of live or folded hands
2. Advise or criticize play before the action is complete
3. Read a hand that hasn't been tabled

The one-player-to-a-hand rule will be enforced.