Pugging as a tank (at least for me on my server) is close to impossible to do. But I would say your in a rather good position to do anything you really want in the game. The Devs said the real difference between NiM and HM Ops is that Coordinating 16 people is far trickier then doing 8 on a HM, other then that the Values don't look much different. I do do feel for you, a couple dps in my guild have a piece of Rakata and I'm just getting into Full Columi myself. Pugging a DPS on a speed run with skilled characters is nothing to be proud of so idk why he is bragging since you are way better geared then he is, and if you were to do that again he would probably cause some wipes here and there.
But enough of my tangent. The only thing you need to worry about with doing NiM mode is the DPS. Since most of the fights apparently require 0 or 2 tanks in KP. You should be well and fine when doing it. Heck you might be able to get into full Rakata faster then your friend and then you have something to brag about since your job is way harder then his.