Mapping cortex sources to DK atlas scouts

Yes, tthat's correct
More info on the source results structure:
https://neuroimage.usc.edu/brainstorm/Tutorials/SourceEstimation#On_the_hard_drive

Also yes
More info on the surface structure:
https://neuroimage.usc.edu/brainstorm/Tutorials/ExploreAnatomy#On_the_hard_drive:_Surface