Well, having read a JML Kitumba draft one can argue that the episode did alter the story rather significantly as is, first by crunching a 2-parter down to 1, adding characters, etc. etc. Given that, tightening and trimming the dialog wouldn't have been any bigger sin.
hmm...not sure what "added characters" you are referring to - unless it's the cameos in the teaser, and our regular Phase II characters...Peter, Xon, etc...who are just featured like the rest of the original crew.
As for crunching the two parter down to one "extended episode" (it's five acts rather than four) it wasn't entirely disrepectful of JML to do so. The two episodes were "writer's working drafts" and, literally, there was one scene repeated (I mean copy and pasted) in the script four or five times. It was quite interesting to see how his mind was working...clearly having the thought "hey, that earlier conversation might fit here better!"
And if you go back to those original drafts, you will discover that the "talking" was cut down considerably. If I remember correctly the first "conversation" took place in the transporter room and lasted a good 25 minutes.
It is, undeniably, still a talky episode in the beginning...and maybe even later. But I did work to cut out as much of it as I thought I possibly could and still tel his story.
(as for TNG the line was "We REALLY haven't had an Emperor for..." so we latched onto the "really". When you think about it, it's a little weird that he would say it that way, instead of "we haven't...) By the end of the episode, hopefully, you'll know why he said it like that...it's only one of the things that "didn't match up in ENT/TOS/TNG about the Klingons we attempt to explain...