I have enjoyed The Crown up to now (less so the last series) and am looking forward to this one. I think it's been very well done up to now. I understand concern for the living, but so much has been (and still is) written about the Royals, and both Charles and Diana courted the media for their own ends that I'm not sure how far usual constraints apply in their case. I don't follow their comings and goings on a day to day level, but recognise that without the media the chances are that the RF would be long gone - they use the media to sell themselves as relevant, and that is a two way street.
Regarding the 'ghost' - I haven't seen it yet, so don't know how well it was done, but I see ghosts as representing the way memories haunt people after loved ones (or not so loved ones) have died. It's maybe an unusual way to dramatise events, but I think it's an interesting one.
On another note, why is Netflix holding back the last episode? I find that sort of thing annoying. As we have the technology to choose how we consume media I wish the providers would let us decide how we like to do it. I feel the same with series that only show one episode a week. These days I am much less likely to watch them than if it's all there to view when it's convenient. Nobody would be forced to see things all at once - those who prefer weekly episodes could still choose to do it that way.