We camp at Myrtle Beach oceanfront. Yes the wind blows 24/7. I usually carport the awning, use DEFlappers, and tie it down. It will take winds over 25 MPH easily in the carport position. And IF a hurricane were to pass by off shore. It can easily, and quickly be returned to the holders, and rolled up. Had to do that once or twice.
As for sand. We use a large awning matt, Also staked down to keep the wind from blowing it away. That, and the door matt catch most of the sand.
I also put a Y on the fresh water hookup, and run a hose over to the awning matt to rinse off with after coming off the beach. Need a place to hang it. so I hang it on the awning support. Stand on the matt to rinse off. Very little sand gets into the TT.
Also. something to think about. Carpet sucks at the beach. So I make sure none of my campers have carpet in them. Tile is GREAT.
Also. We don't worry to much about Flying Bugs at the beach. the wind usually blows them away.. Which leads to the next thing. A fan, and good sized fan. Just in case the wind ever dies. A fan under the awning is worth its weight in gold when the wind dies