1) no, there will not be fungus, unless you have soaked it in a very humid environment hurhur.. short periods ok la
2) come back from beach - you might want to wipe the exterior down with a cloth, and cover the lens with any form of filter - preferably one which helps your shots in some way, if not uv will be great i suppose, i hear the saltwater is not very good for lens coatings, hurhur
anything you should take note of, my guess is do some research on what you might need and what you don't, don't just bring everything and use half of your equipment, lugging it around is fine and dandy but you feel really stupid when you only use half
if you are going to a not so safe place, keep your eyes open, normally people won't just strike on impulse, they will plan so beware of overly friendly/attentive strangers, etc, the usual la
my advice is to bring a tripod no matter what. god knows i regretted not bringing tripod for a few trips