Is it safe to share my view key with my accountant or business partner? Can a view key be used to steal my funds?
A view key can NOT be used to steal your funds. Think of it as a way of granting someone "Look, but don't touch" access.
It is important to remember that the viewkey allows you to see only incoming transactions, not outgoing, so it cannot grant you what would be considered a "live" view of the address' holdings.
Therefore a viewkey could safely be shared with your accountant or business partner, but they may also be aware that what they see may not necessarily reflect a true count of what the address contains.