Starfire's NPC Additions added traveling merchants with guars, added various classes of NPCs to spawn and had the teleporting NPCs. Earlier this year Jac produced a Lite version that eliminated some groups of spawning NPCs (notably vampires and DB NPCs walking around in cities in broad daylight) in response to my request in this forum - I felt those two types of NPCs were just too out of place wrt MW lore. I don't have the link handy, but I'm pretty sure it was the Starfire thread where this general topic was discussed before. I use the Lite version in my game and am happy with it. I don't notice guards patrolling areas outside the city boundaries with the possible exception of Seyda Neen. I do notice one or two NPCs at the entrance to Ebonheart and on the city of Vivec's north entrance (VFQ bridge). I don't know if their presence is due to Starfire Lite or vanilla MW.
One downside using Starfire NPC Additions is that it was pretty script intensive in some areas, imo. I always had FPS problems in Balmora.