I am taking a different view on matters(Sorry if off-topic.) If the biggest way to expose F1 is through TV. Where the team's and event's sponsors will get the most exposure and also from selling the rights to media groups.
Why not get rid off the tracks that produce the lesser entertaining races, keep the ones where the racing is exciting. To find out which new events are exciting or not, offer a new a promoter/track a 3 year contract to see whether the racing is exciting or not. This may produse a high cycle rate of tracks but i think going to new tracks is exciting for the sport.
By keeping the exciting races that people will watch, will gain more exposure for everyone. And therefore get TV ratings up, which means more exposure for sponsors and hopefully cheaper ticket prices and less goverment money spent(specifically the Victorian goverment). So the end result would be that the teams get more tv rights money, sponsors pay more, ticket prices are cheaper so more people would be able to attend races.
I don't want to see any more racing from Bahrain or Valencia, these races do not excite me.