I made a big open room using the generic tileset, with little hallways branching off for all the main quests in my land. I then put triggers at the head of each hallways saying what quest it went to, then at the end of the hallway I put a custom trigger that teleports you to where you need to be, sets up the quest and moves/enables/etc anything that needs to be for that quest. That lets me and my testers jump into the main quest at any of the 9 quests, instead of playing for hours to get to one spot.
As for people, I'm not sure if this would work for venders, but I simply made copies of all of my characters that inherit everything from their base (Except for factions and such so they dont fight eachother).
That way I can run through this one room and test all of their voice stuff to make sure lines are working and sounding good.
Hope this helps.
