Experience gains from quests

[Hety]

On my new playthrough i decided to get as many levels as possible for  my main char so "save" possible experience, coz all xp is divided between ypur party members. But atm it looks like there is some kind of multiplier for experience you get from quests. So few questions:

 

Do quest rewards scale according to group size?

Do quest rewards scale according to difficulty level?

 

I do know that gains for opening locks and disarming traps do not scale at all.