Some vendors respawn almost instantly. Some take a few minutes where you almost start to worry they won't respawn at all.
I had to spend time in NRo recently. My toon lvl'd up and needed to up skills.I begged off of the Devish, orcs, mad men mob quite successfully raising my lvl. Begged off Dorn for fun cuz he attacks. I was way over the lvls there, so the mob were reluctant to attack. And I begged animals too. Got fail message, so leads me to believe they work for skill up too.
