I know how to reconnect to an image or audio file that has been moved or renamed. But suppose I move or rename a folder with 50 images. Do I have to open Premiere and reconnect with each asset, one at a time? Or is there a way to expedite the process?
You should only have to relink one of the assets per moved/renamed folder, Premiere will then automatically check for any other offline assets in that directory and relink them. Depending on your version of Premiere Pro there will be a checkbox in the Missing Media dialogue that will allow you to toggle that behaviour:
Premiere has also been made smarter successively. For example, the CC version will remember the last 10 locations of your assets and check those automatically in case of offline media. It might also relink all your assets in different folders if the overall folder structure of the project and/or the relative path from the project file to the media file haven't changed, but I'm not sure about that.