I wouldn't say I don't have an opinion. I can a lot times see where others are coming from, but I don't agree. Normally I offer a contrary opinion/idea and see how they react. Normally in a way that makes it sound like I disagree which isn't necessarily the case, but I love to argue so I never come off not opinionated. Hardly. But do I usually have a strong opinion? No. But arguing is just so much fun.
As for the OP, NFP sounds right to me. I think several types could fall into that though. I would say P before J though. F before T, although it depends on your reasons for understanding others. I could see a T just being detached enough to see others opinions and not really care. I would comment on S versus N, but I am tired of people not really understanding S (myself included) so I will just leave that one be.