1) There are several different entrances so trying to seal off the whole area is a lost cause. The teleporter is the only entrance from other sectors though.

2) I've already given you an estimate. More npc direction will be given once other groups have returned to the area. Until then, please don't overcomplicate things.

2) The shop area would be fine to set up in. Its basically just a store front with stuff kept in back supply rooms.