St Barths is without a doubt the safest island in the Caribbean, and one of the safest places in the world.
There is virtually zero crime, beyond petty theft. You can go anywhere on the island night or day with no fear whatsoever for your personal safety.
However do not leave valuables in your car, and use the safe in your villa or hotel.
There are no pickpockets, muggers, dealers or street traders to hassle you.
The roads are narrow and often steep and winding. Small 4x4 rental jeeps are the vehicle of preference and renting scooters is not advised.
respect
St Barts is very French and very traditional.
As such it is customary to say "Bonjour" on entering a shop or restaurant and "Au revoir" on leaving.
Similarly on passing a stranger in an uncrowded environment.
Men shake hands more frequently than in "Anglo-Saxon" countries, however only on the first encounter of the day. A handshake will be declined if you have already met the man on the first day.
For both men and women meeting women a kiss on each cheek is customary La bise. Right cheek first. The same once a day rule applies. A man shaking a woman's hand only occurs in formal business situations.
If meeting a group of people one is expected to greet each each and every individual with either a kiss or a shake of the hand as appropriate.
Honking of horns is considered to be highly impolite.
talk
French is the official language of St. Barthelemy. Many residents, especially those involved in the tourism industry, also speak English.
Creole is widely spoken on the windward side of the island, and a variety of Patois across the leeward side. These languages are sadly dying out in favour of French.
Up until recently Gustavia was English speaking and the creole quarter, La Pointe, remains so.