As a general rule, revolvers don't have safeties. They are not carried in a cocked condition like auto loaders often are, and don't need a safety. When not cocked, revolvers take a considerable trigger pull, normally in the over ten pound range, which provides for safety. This doesn't stop action writers from referring to the safety on a revolver, or the spare magazines, either.
Hopefully, someone can help with your first question.
Rick