Be good to be specific with your questions. I can field most of them. Please don't answer questions unless you are 100% sure because you've either read up or lived in Korea.
For example, the King shown is King Injo.
There were in fact an overthrowing of the last king.
There was an uprising against King Injo.
Read about it here: http://en.wikipedia.org/wiki/Injo_of_Joseon
All levels of Korean are used here. In terms of drama timeline, this comes after Hong Gil Dong. Because Hong Gil Dong is set with the previous King.
If you have questions about clothes, etc, ask. ^_^
I've also been to most of the palaces they've used in this drama. Sad, because I know which shot is which and which dramas they used that structure for before. ^^;;