The game definitely lack some side quests in my opinion and some of your ideas looks very interresting.
There's also very little to no point visiting some area of the map (swamp if you haven't talked with Ethel, North if you haven't got Lae'Zel in your group).
Side quests could also serves the exploration.
Someone asking components you can find in the swamp, someone asking your group to kill the gnolls, someone looking for something he has lost while fleeing,...
It becomes better in the underdark but especially on the surface, the game lack more "usual" side quest in my opinion.
