Using Wi-Fi calling can I call an international land line for no charge?

No. Wifi calling, which is a carrier feature, still uses and applies to your regular cellular telephone calling plan. It just routes the call via wifi when the cellular signal is weak or not available. But nothing about carrier wifi calling changes how you are billed by your carrier. As far as your carrier is concerned, a wifi call is no different than any other cellular call - the feature just lets you use your cellular plan where the cellular signal is weak or cut off.

Wifi calling is not VOIP calling. Wifi calling simply allows a wifi/internet connection to your carriers cellular telephone exchanges.

Ask your provider. We don't know.

International rates would likely still apply. For more definitive answers however, you should check with your cell carrier.

Check with the cruise line as well. Some partner with specific carriers to offer cell service from the ship. Usually, surcharges apply though.