I like people, too. I think above all, having deep connections with people is my absolute favourite thing. Helping people is a big plus, and seeing them feel good about an interaction is very important to me. However, the difference I see between myself and xNFPs is that I don't flirt. I can keep cool boundaries to let people know that, yes, I care, and they can rely on me, but I'm nothing more than that.
To me, the flirtation is a means by which to gain acceptance and validation -- things I don't desire much of except by those I'm extremely close to, like beloved family. If anyone ever reads anything else in my actions toward them, I set the record straight any way I can. If that fails, I slam the door on them; it's far too risky to go on, especially because I have a tendency to be used.
My mom was an INFP, her love of people and her [honestly rightful] desire to be accepted by people she cared about was a major pitfall. My boyfriend is very similar, being an ENFP. My aunt is also an ENFP and struggled with such social issues, being way too much of a flirt. I understand her, but my uncle still has her feeling like shit for being 'slutty'.
In short, I see all sorts of negative outcomes to the xNFP love of people and validation, but I'm sure it works out sometimes. As an INFJ, I also struggle with the airy, inconsistent, histrionic flightiness in relationships and friendships. I've gotten pretty pissed at my boyfriend for neglecting his friends, and me, especially during times of need. I think all it takes is a little balance and self control, and any xNFP who masters that is a very fine individual all around.
