User blog comment:Zelron/Helgen Hometown (Dragons bring down my property values!)/@comment-4057437-20121128070410/@comment-4057437-20121129045156

We didn't say to clear all of them out. Clearing out the bandits aboveground has no effect on the quest. We know, we've done it. Either way, Pinewatch does become a candidate after the quest has been completed. (Only the bandits underground respawn.)

As for opening trade routes, one could recruit some Khajiits to form a caravan.