Just because CH is open to the public, it doesn't mean ALL of it is open to the public. My guess is, the reception, dining and drawing rooms. I read that POW had part of CH converted into a self contain flat, which means NONE of the public would have access to that.
that's exactly right. its the same in all the royal palaces (and castles) that are open to the public.
I suspect when PH is meeting up with CD it wouldn't be at her flat because it has been public sometime she has been living in Belgravia, therefore that surely would be an open invitation for those who mean to harm?
i dont actually think it would be a huge security problem. he and the other royals live in far more well known addresses in London after all.

Belgravia is a big district and although i'm sure paparazzi have her address i've never seen it published.
Then why were they going in the private entrance? Plus do you know Harry wasn't there?
they were having a private visit with Harry. i think wannabe is just pointing out that it's open to the public for a few months in the year. although the public rarely gets to have tea with Harry while visiting.

usually. he did have tea with cancer survivor Nicole Dryburgh and her family at Clarence House.
My date with Prince Harryand i've just remembered that Matt Lauer mentioned that Chelsy was at Clarence House when Harry and William gave the pre-concert interview the year before.
so yeah....like any and every bf and gf they hang out at each others houses. now that Chelsy has a London flat of her own (rather then staying with friends as she used to) its not all that surprising that he'd be able to spend more time at her place.