Is everything gluten free?
The great majority is and is labelled as such. Check the individual product page if you are coeliac — certified gluten-free status is stated there.
Are the macaroons dairy free?
The plain coconut macaroons generally are; the chocolate-coated ones are not. Allergens are listed on each product page.
Do they contain nuts?
Some do, and the range is made in a facility handling nuts. Anyone with a nut allergy should read the allergen statement carefully.
How long do they keep once opened?
Reseal the pack or move them to an airtight tin. Gluten-free biscuits dry out faster than wheat ones, so they are best eaten within a few days.