Okay I've muddied things right up now, dammit!
I would have thought the quote I gave better described Fe-dominants actually, and have heard of INFJs putting less 'effort' into relationships than this. The following quote (from the EIDB, apparently) is supposed to describe a 'typical' route for a less healthy INFJ, though not necessarily the only one I guess.
"INFJs tend to withdraw from reality into a fantasy world of their own, which gradually gains importance as they become dissatisfied with their real life and the people in it. While fulfilling the demands of their outer commitments, they harbor secret criticism and the feeling that their imaginary world and the characters that inhabit it are more important than the actual people in their lives. They can end up living almost exclusively in their imagination, resisting reality with a defensive attitude, feeling like a misfit and spending enormous amounts of time exploring and discovering their deepest hidden fantasies and emotions. In this state, they might be attracted to majorly defective people and environments, which they perceive will truly understand and appreciate them."
Apart from the last sentence this is basically me, though it could probably apply to INFP as well. Currently I fulfill my obligations to the minimum level to ensure I am not (at least openly) criticized. I do respect some societal norms and 'shared values', the point I was trying to make was that I am not the type of person who would willingly just arrange my life around others, unless those others had special needs or were children. I'd take the possibility of being an INTJ in a dom-tert loop more seriously were it not that I am predominantly pre-occupied with the intra/inter personal, though if INTJs in such a loop start becoming more interested in the personal it would be worth entertaining (I've just never heard of this happening). For ISFP I'll re-think though.
I've done two Jung tests before, and both put Fi tops. I don't take the results seriously, though I suppose it's another piece of evidence of sorts. But I'm increasingly having trouble seeing myself as anything other than a J-type (I am actually a huge fan of 'structure', even if I have a funny way of showing it), so this is hard, but I'm not entirely convinced that an INFJ would never use Fi in preference to Fe. It's not like I don't respect shared values at all, and partly (but certainly not entirely) judge my own actions against social norms/shared values, as I'm often not clear about what's right/wrong anyway.
Perhaps I should post a thread in the INFJ section to see what they think about using Fi.
Hope I haven't confused you further.