If you got a dedicated healer, you can pretty much just pound out the damaging shots in full DPS gear without being in too much jeopardy. Distracting Shot has unfortunately failed quite nicely to scale with our level and DPS. Low threat per shot, so a steadyshot would usually give you more threat. I can't remember the number, but I think it was around 800 threat or so.
When we started out Gruul's Lair, we were sadly undergeared. That meant that me and another Hunter shared the tanking. Using Feign Death alternately, we just shared the punishment until it was his time to die.
As for NR, I've never actually used it myself when tanking him. A fairly new Hunter in the guild got himself 300 NR, so he has become the preferred tank these days if he is available for our weekly run. So it certainly helps, but it isn't mandatory if you got a healer on you. However, if you can obtain 300 NR, you can set the healer to heal something else and mostly just offheal on the Hunter Tank.