I quite liked the sound of this change, except for the timer where you're talking to the NPC for 15 secs, so if say, someone comes up to you and says 'Excuse me, can you tell me...' while you're talking to an NPC they'll probably give up on you before you can say anything to them. Maybe a hotkey is needed to break off talking to the NPC, or maybe the NPC could recognise a sentence with 'bye' or 'goodbye' in it to show that you're finished talking to them. Okay, 15 seconds is not ages, and is probably about the minimum you need to make the new system work smoothly, but it could seem a very long time to wait from a response to a player who may be afk (I suppose you could jump up and down or something to show that you'd heard the question and would answer when you could).
Anyway, I might have hit on another problem (related to what bilbous says above), or maybe there's a problem with the quest now, or maybe I'm just being dumb, but I'm just trying to complete a quest for Harnquist and got stuck when you give him something, he says he'll teach you some more, OK?, so presumably you're supposed to respond Yes, but I can't get this to work in the new system. Hopefully the following to illustrate the point is not too much of a spoiler:-
[I give Harnquist the X he's asked for]
Harnquist tells you: Ah good. It is important to ...blah blah blah ... If so, find a Y for me and bring it here. OK?
Aelfwine says: Yes
[No response from Harnquist]
Aelfwine says: Yes Harnquist
Harnquist tells you: Sorry, can you use a simpler but complete phrase?
Aelfwine says: say Yes
Harnquist tells you: Sorry, can you use a simpler but complete phrase?
I've tried it three times now, after the first time making sure I said 'Hello Harnquist' before I gave him the X (again - some more of my hard-earned goods gone!) so that he should already have been talking to me, but the same result. Giving him the items seems to cancel his attention, then if you get his attention by using his name again he doesn't realise he's just asked you 'OK?'.
Any tips?