Your finding make me feel terrible frustrated, so the forum is complaining about this topic almost from day 1 and the stuff is there (better dialogs I mean) and no one took some time to check why is not working. No one on the team knew that your wife shouldn't call you 'my lord'?The game's dialog mechanic uses a system "tags" and "weights" to determine which line an npc should speak, but currently when the game loads in the all of the dialog lines, it hardcodes the weights of all of the associated tags to a value of 1 instead of using the weights that are specified in the xml files.
That essentially blocks a certain portion of the dialog lines from ever being chosen, and it's also the reason that your spouse won't call you wife/husband, because the "PlayerIsSpouse" tag is supposed to have a weight of 10 for those greetings, but is instead assigned a weight 1 when they are loaded in. It also causes dialog lines with negative weights to be selected in the wrong situations.
It's anyone's guess whether hardcoding it like that is just temporary while they work on it, an oversight/bug, or they switched to a different system and haven't worked out all the kinks yet ?.
Also, I think some of the conversation tags are either bugged or redundant, which has an effect too.
Edit: It's the LoadFromXML method in the GameTextManager class.
Honestly the time that TW has invested in half backed stuff is incredible, if they were able to polish all these the game will be 5 times better but it seems that they don't know how to do it... again seems a poor leadership problem.