:I agree for the most part, but question the final point re. "monarch."  Of course, talking about a general monarch or monarchies (ie. "a monarch reigns over a realm" and "European monarchies were overthrown by fascist movements") should not be capitalized; but, when speaking of a specific monarch or monarchy (ie. "Queen Elizabeth II is the British Monarch" and "the British Monarchy is over 1000 years old") should the words not be capitalized?  It is the Canadian Monarchy, but a monarchy; no? 
 :I would also add "Dominion" to your list when referring to the non-UK Commonwealth Realms prior to the 1970s.  JDM has been arguing for the de-capitalization of the word at the article Dominion.