re: changing places.
You think its easy to stand whole day 365 days a year at same spot and offer these services? The npcs have their own things to do too =P they need to go get fresh supplies, level, bank, and even pee

They also like to walk around and talk to each other
but serously
When I was populating the newbiee area, the only thign I originaly placed was quest npcs and needed vendors. Later I reliased that wihout access to THF hub, I will need the class trainers too. I realy did not wanted to make 16 new npc who will do nothing but stand around whole day - so I made all quest npcs into trainers, and only added trainers when I run out of quest npcs.
Also, not to overcrowd the entry area, the trainers were spread between the "towers" where banker is, the front yard, and "to the hole" passage.
As far as rotating locations - this is just how I work with spawn points. I make a single spawn location and just nodes to it. It makes my work easier of not hvaing to track individual spawn info per each npcs, and makes cool impression of npcs "walking around"
