Part one of your question has been discussed before, -- but it was a tangent, and might be hard to look up, and it went of on tangents, too, so there might be stuffed we have missed.

part 2, is brand new topic.. and i haven't pulled out my dictionary, but i think ward as in ward room goes is related to the meaning of ward as stewardship-- (a lame example, Robin was Batman's ward in the comics!) the idea that a king had stewardship over a people, and was responsible for them -- prisoners today, are still called 'Wards of the state' the state provides food, clothing and other items, and the same is true of children in foster care. the foster parents are paid to care for the children, the childern are wards of the state.

i suspect a Wardrobe was a group concerned with the states duties, and might have also been a privy councel. someone or some group of people very close to the king, who help him with his duties, especially internal affairs. Oopps, domestic, ooops that can be misleading too, Homeland duties.
in US it would be something like the State Department, and now i suspect in England it would be the Home Sect., as for the robe part of a Kings Wardrobe.. i don't know.