No, my niger has never bit me. It seems to be very timid and shy. It gets easily 'spooked' and hasn't distrurbed anything else in the tank. However, I've only had this little guy for about 10 weeks.
The tank I have is 90 gallons with around 80 pounds of LR. Currently I have a Dog Face Puffer (6-7 inches), a Niger Trigger, Blue Starfish, a couple Damsels (that I've been trying to remove for weeks now!) and a mated full grown pair of Percula Clowns. Not to mention the crabs, snails, etc... They all get along extremely well and nobody bothers anybody at all. I don't want to overcrowd my tank, but I really like to get a Lionfish. That's why I'm debating on getting the Dwarf Lionfish.