You can easily make a path a selection, and make a selection a path. You have a lot of flexibility, because you can also make a mask a selection, which you can make into a path, or you can Command-click (ctrl-click on the PC) a layer with an object isolated on it, and it will make a selection out of the contents of that layer. You can do this on any layer, and then use the masks panel to refine your selection.
To make a selection into a path, make a selection, go to the paths panel and click on the flyout menu and choose Make Work Path. The lowest you can fit it is .5 pixels, and then your selection is now a path.
In your paths panel, right click on any path layer and choose Make Selection.
