If the beach is crowded, land the kite outside the surf break, disable it and then swim in. Do not lay kite lines across anyone's path. Stay away from people. Don't call 999 or the coastguard if a surfer's kite is down and he is paddling in. Every takeoff is optional.
Every landing is mandatory.
Flying isn't dangerous. Crashing is what's dangerous. It's always better to be on the beach wishing you were out on the water rather than out on the water wishing you were on the beach. In the ongoing battle between kitesurfers going 30 - 40 knots and the ground going zero knots, the ground has yet to lose. Always try to keep the number of landings you make equal to the number of take offs you've made.