From my point of view, it would be great if the program just followed normal standards. If the currently selected item can be copied, then it should have all the appropriate ways activated, Ctrl-C, context menu Copy, Edit menu copy, toolbar button copy...
As far as you specific example question, it depends on what is selected. The recipe is selected when the folder view is active means the whole recipe. If an ingredient line inside a recipe edit is selected, then just the ingredient is copied (so I can paste it into another recipe).
Again, just my opinion. I'd be happy to evaluate and make recomendations if you are willing to take on the task.