Thanks for your answers and thoughtful comments very helpful.
I suppose my thoughts were - I do everything through light room, I import from camera Nikon d700/d600, edit/delete pictures as required to a "final picture" "move" final raw pics to external hard drive via light room -(backed up also to cloud) and export/import to have much smaller JPEGs on laptop which can be used for slideshow, or apple tv. sharing etc. Light room still has the record of where the original is which can be edited or changed further at a later date. My Applemac then can easily accommodate my 50000 "final" pictures,asJEPGS, take downloads from the camera for editting, and have a picture stored which can be printed, shared with others without carrying an external hard drive everywhere with me.
Hugh