Ah I see, that makes more sense, ambiversion as a description for someone who is close to middle but actually has a slight preference. The thing is there may be any number of reasons why someone may behave introverted or extraverted, that's why behaviour and "seeming" are irrelevent, with the functions what is most important is a natural inclination, even if this natural inclination isn't reflected in behaviour. This is why tests are only useful as an initial guide, as your natural inclination doesn't always show up in your behaviour or even your test answers due to interference from outside sources (cultural roles and norms etc.). MBTI is only an indicater, the goal is to find your true (pure) type, how you truly are when free of all external forces. This is why I think it's very hard to accurately guess the types of others, your true type may even be hidden from yourself under layers of social conditioning.
Could you give me examples of how you use both intuitive and feeling processes before any others? Are you sure you're not interpreting your Ne as both Ne and Ni, when it's really just Ne being versatile? Same goes for Fi/Fe. If you are just taking that from test results, I believe that functions can interfere with each other when answering a question, for example; questions asked to determine Fe can be answered positive by Fi as it's the F which counts, poor test design probably, hmmm it's hard to explain this part, hope it makes sense.