The province, as the rest of Belgium is a very safe place. However, some fights might occur at the end of village 'bals' where heavy drinking is involved. However, those happen usually between local youngsters, and basic precaution will avoid any trouble, and you will find your stay a very peaceful experience.
French has been the official language of the province since it was imposed in schools in the nineteenth century. Nonetheless, a number of traditional languages are still spoken or understood by a part of the population, who mostly live in rural areas:
The Ardennes version of Walloon in the Ardennes.
Gaumais in the south.
Luxemburgisch Lëtzebuergesch, a Germanic language that is closely related to German, but has several French loan words, is spoken near the border.
Dutch is widely spoken in most touristic places, as a large number of Dutch and Flemish tourists visit the province each year. English is more widely spoken or at least understood by young people across the whole province. German is spoken by some people who live near the border with Luxemburg.