Leave the fuel selector alone unless you're prepared to lose that engine...any time. Not just over water.
Guppy good point but its not just engines. The earlier citations in particular have a crossfeed selector on the panel which has the tiniest pin holding the selector to the rest of the gubbins.
Break that off and you would merrily watch fuel burning at a remarkable rate with both jet engines feeding off the one tank.
A friend carries a set of thin pliers so that he could turn the selector should it ever break.
From memory I think there was an allowable 500 ibs difference between sides and after that the aircraft would become uncontrollable 500 ibs is no time in the citation. A real emegency situation. Fuel should be handled with extreme care
Pace