I'm glad you made an updated rigging how-to video. Pictures speak volumes - and entertaining too 
I'll add that you can turn off the feature that makes unattached meshes move with any bone- in Keynote, click on "option" and uncheck "Auto-Anchors". Those auto-anchors have gotten me into trouble by making it seems like my model was riigged correctly when it actually wasn't.
I'll add that you can turn off the feature that makes unattached meshes move with any bone- in Keynote, click on "option" and uncheck "Auto-Anchors". Those auto-anchors have gotten me into trouble by making it seems like my model was riigged correctly when it actually wasn't.