There are waypoints in the GIT file (003EBO.git in RIMs) that designate the spawn points, then the NPCs are spawned via the OnEnter script. To change the locations, you'd have to edit the GIT and recompile the entire module in a MOD file. It's not difficult, but it wouldn't be compatible with any other mods that do the same. There isn't a map for that module, so you'd need to do it manually with K-GFF, which can be tedious. Also, some of them have heartbeat scripts that might override any changes you make - though Mandalore isn't one of them.
Adding things is easier, because you don't actually need a waypoint to do it -
CreateObject(OBJECT_TYPE_CREATURE, "object_template", lLocation, FALSE);
- you just need a location. You can use GetLocation on any other object, and you can also create a location with exact coordinates, so you have a lot of choices for spawn points. You also have a lot of choices for how to fire the script. One point I like to use is the lightsaber conversation with Bao-Dur, since that fires right when you get the ship back.