I love the beach and sea as for launch there is always a plastic table lying around you can also use for take offs and hand catches really are not that hard even in winds.
i fly out 4km often to video islands that are 4km away from where i am.
watch the heat it kills battery power,
Do not overfly children as they do tend to be unpredictable. having said that i have never personally experienced any problem with kids and only one problem with an adult that i was not actually near and who came over from 100m away to the Mavic.
try to fly early as the light is good and the beaches are emptier and normally winds can be lighter, Check tides in and out as that can also be a factor you can wander out 200m and take off but if that tide is coming in and you have been out 20 mins your home point may now be under water.