How many pratices should a team have prior to a tournament? 1 per week, 2, 3 or more?

as well as the level of the tournament, expected competition, and the team's goals. If it's a top-level team in one fo the older Classic or Athena age groups going to a top-level tournament and needing/hoping to do well, the 3x per week with maybe one of those being an abbreviated practice and a scrimmage.
There are a lot of variables that play into it and your coach is generally going to dictate the preparation.

how long did they have off before? when was last game? many factors to consider

How many do you think RM?

Expections are high for out of state tournaments. Parents spend a lot of money (not easy in this economy), take vacation time, they expect results. If coaches don't prepare the team, it looks bad on the coach, club and team. Unhappy parents can create a lot of trouble for a coach.

3 practices before a tournament this time of year can burn kids out and cause injuries. Stupid.

With no games on wkends, th 4rd practice can be set plays, shooting light workouts, just to keep the kids moving. It is what the pros do.

Talk about a DumbA$$!

If they loose it is the coach that looks bad, not the players.

If the players are prepared to the best of their ablility then whatever happens, happens. By your comment any time a team loses it's the coaches fault? Sometimes the best team does not win and last time I looked the "team" was made up of players and coaches.

not prepared properly then they will absolutely blame the coach.