Items are as strong, but as well, as fragile as glass. You better prevent and take good care of it, they will be grateful and stay trusted partners for a long life.
Even oiled or waxed, wood doesn't like humidity, big difference of temperature and sharp items like cutlery.
Aging, items can get darker of colour.
To clean is a dry towel often good enough, use sometimes oil or wax to get the wood again shiny. Concerning allergy, avoid walnut oil .
By item, I'll give you customized advice for maintenance. Don't hesitate to contact me for advice!