How did it work in BG1&2 ?
I never noticed disapearing poeple... Does they all have a house and a bed ? I don't think so but i'm not sure, I never try to follow them...
Wasn't in Taverns, bit others were just de-spawned iirc. Certain missions could only be done at night, certain encounters only happened at night etc...
I can't remember people "sleeping", been a while since I last played though.
There are people sleeping, but not so much.
I think it was something like in a "familly" (those living in the same house), some was in the house doing nothing during the day, and they were somewhere else at night, and vice versa...
There were a LOT of houses, and a lot of tavern, with lots of beds, but I'm nearly sure the majority of them don't sleep during the night.
Are you sure about the spawn / de-spawn ?
I' playing the EE for the first time now and I played many times but I never noticed that.
Variable weather and day/night cycle is something that really adds atmosphere and variety as you said,
I think it's really important in a "credible" RPG world. Of course, I'm really not fan of multiplayer, so the explanation does not convince me...