In Germany we now have a surge of censorship changing the old classics through eliminating such politically incorrect terms. "Negro" is not allowed to be used anymore, because it was said in an devaluing manner although the word itself just means "black". It think the changes has to be made in the minds of the people not in the classics.
Laddie has the following meanings (you guess it):
1. a boy
2. a term of affection for a boy or youth
3. a male sweetheart
A Laird ("Lord") is a high ranking person owning a large amount of land. He is not necessarily a clan leader, so I wonder why most writers use this term soleley instead of Chieftain, although the latter is meant. My, do they all have to be hulky men in chief positions? The authoress Monica McCarty is a positive exception with regard to both.
Depending on the time period or the origin of the speaking person she or he will have used the Gaelic term Tighearn I haven't read in any romances aside from my own. Seems that I'm a history buff when it comes to research.
Lady and Leddy seems to be have been used simultanously at past times. Though I never read "Leddy" in any Romance novel. It means lady, of course, and is the estate title given to a female landowner or wife of a landowner.