I have played and finished DD once, and am going threw it again trying to finish up all the little things that i didn't do the first time threw.  Honestly the game was over before i knew it.  I noticed on the game, both times threw, that there are more than a few people that contribute conversations about a quest. Yet because i couldn’t remember what they said, or whom they where I let the quest go unsolved. If you cant remember who contributed what, there is no point to having a conversation log. My suggestion is this, when you look at your quest log it will say something like.   2nd day  Find a solution to the plague problem in river town...  I think you should be able to click on that title, and be able to see a list of all the conversations pertaining to that quest.  Instead of having a list of conversations, like Goemoe at 1st day.. ?? i have no clue what he said that day so i have to read it, NOPE wasn’t what I was looking for, NEXT Person.. NOPE not him either... WHO said blah blah blah, about me tlaking to so in so? I have no idea? How do I find it to finish the quest? i don’t.. Having the quest menu run the conversation menu, would make things a bit simpler, and you would be able to get rid of an icon, I’m sure most people don't use much anyways. And in the end make things a little simpler.  
Aurrous 
 P.S. i hope someone understands this insane ranting.