I somehow missed this post. So good it showed up on the first page.
Once again you said it so well. I agree I found it trivializing the whole relationship between AR and it did actually put me off that I did not watch the next few episodes.
And even without all the points you have made if we are talking facts then they were engaged (she did accept the ring before the shooting) so even saying ex-fiancee wold have been fairer. Just as she is being referred to as SiD's wife and bhabhi regardless of circumstances this occured, in the same way give AR's relationship the status it deserves.